Development of a Fish-Based Index of Biotic Integrity for Wadeable Streams in Southern China
弹性城市指标体系
City Resilience IndexCity Resilience Framework April 2014© Ove Arup & Partners International Limited 2014AcknowledgementsOn behalf of the study team, I would liketo thank The Rockefeller Foundation for giving Arup International Development the opportunity to undertake this study. Our special thanks go to Dr. Nancy Kete, Sundaa Bridgett-Jones and Lily Fu for their support throughout. We would also like to thank the Rebuild by Design, 100 Resilient Cities – pioneered by The Rockefeller Foundation– and the Asian Cities Climate Change Resilience Network teams. Their comments and feedback have been very valuable toour work.Our particular thanks go to everyone who contributed to the fieldwork, especiallyour local partners: Fundación Alto Río (Concepción, Chile); GIP Pacífico and Findeter (Cali, Colombia); City of New Orleans and the American Red Cross Southeast Louisiana Chapter (USA); Arup Cape Town (South Africa); TARU Leading Edge (Surat, India); and Mercy Corps (Semarang, Indonesia). Their assistance during the fieldwork made a significant contribution to the final quality and outcomes of the study.Jo da SilvaDirectorArup International DevelopmentOn behalf of Arup International Development’s study team: Sachin Bhoite, Kieran Birtill, Stephen Cook, Sandra Diaz, Vicky Evans, Andrea Fernandez, Laura Frost, Sam Kernaghan, Ashlee Loiacono, Braulio Eduardo Morera, Geoffrey Morgan, Elizabeth Parker, Jo da Silva, Samantha Stratton-Short, Flora Tonking.Graphic design: Charlotte Svensson.Unless specified, all images are copyright Arup.© Ove Arup & Partners International Limited 2014(Front cover) Cali: Centro Administrativo MunicipalForewordIn 1958, Jane Jacobs, a community activist, received a Rockefeller Foundation grantto expand upon her ideas about how a city should look, feel, and work. The book she published three years later − The Death and Life of Great American Cities − transformed how city dwellers, urban academics and policy-makers think about cities and urban planning. Jacobs challenged the prevailing assumptions of what makes a city thrive. Over the past five decades, the values and ideas put forward by Jacobs and others have been profoundly important as questionsof identity, voice, inclusion, access and opportunity have been negotiated in the context of dynamic urban growth and globalisation.This legacy of progressive urban thinking becomes even more crucial as we lookto the future. Just as cities are hubsfor innovations and investments that expand opportunities, they are also living laboratories forced to confront challenges of increasing complexity. Indeed, the role of cities has become central in debates around our planetary boundaries, economic futures, social stability and climate change. What and who makes a city resilient – and not just liveable now or sustainable for the long term – has become an increasingly critical question, one we set out to answer in late 2012 with our partners at Arup through the creation of a City Resilience Index.The Rockefeller Foundation has been pioneering work on climate resilience in both rural and urban regions for more than a decade. By 2012, the idea of resilience as the critical lens through which to consider not only climate change, but also disaster risk reduction more generally, including financial shocks, terrorism and slow-moving chronic stresses, was gaining traction globally. But, producing a meaningful index for something as complex as the resilience of a city is fraught with reputational, conceptual and execution risk. We stumbled again and again on major conceptual and practical challenges.We found potential partners ready to jump into the metrics and indicators, but few with the experience to work with usto understand what does and does not contribute to urban resilience. We risked investing in an index that measured and compared cities based on available data, but did not necessarily help cities better understand and assess their own resilience.We found perspectives were siloed, shaped by experience and expertise in one or another aspect of resilience, disaster risk reduction, infrastructure resilience, climate change, national security or business continuity. What Arup has been able to bring is thought leadership and the capacity to create a comprehensive framework that reflects reality. A city’s resilience depends on its physical assets as well as its policies, social capital and institutions.This report presents the inclusive framework for articulating city resilience that the Foundation was looking for, to underpin the City Resilience Index. It has already proven useful in the agenda-setting workshops in cities across the globe that are participating in the 100 Resilient Cities Challenge. These workshops, in turn, have helped and will continue to help shape the framework and contribute to the final phase, developing the indicators and variables that will comprise the City Resilience Index.This framework will form the basis of a tool that should enable all of us interested in city resilience to convene around a common understanding of that idea, and begin to‘baseline’ what matters most for making cities more resilient. Both the framework and the index are intended to facilitate a process of engagement with and within cities that generates dialogue and deeper understanding. Ultimately, this will leadto new ideas and opportunities to engage new actors in civil society, government and business on what makes a city resilient.Dr. Nancy KeteManaging DirectorThe Rockefeller Foundation1 City Resilience Framework - The Rockefeller Foundation | Arup“In order to get a grip on it, one must be able to relate resilience to other properties that one has some means of ascertaining, through observation.”Martin-Breen & Andries (2011) Resilience: A literature review. The Rockefeller Foundation: New York City, p. 11Understanding city resilienceWhy city resilience?As the 21st century unfolds, an increasing majority of the world’s population will live in cities. Human wellbeing in cities relies on a complex web of interconnected institutions, infrastructure and information. People are drawn to cities as centresof economic activity, opportunity and innovation. But cities are also places where stresses accumulate or sudden shocks occur that may result in social breakdown, physical collapse or economic deprivation. That is, unless a city is resilient.Cities have always faced risks, and many cities that have existed for centuries have demonstrated their resilience in the faceof resource shortages, natural hazards, and conflict. In the 21st century, global pressures that play out at a city scale − such as climate change, disease pandemics, economic fluctuations, and terrorism − pose new challenges. The scale of urban riskis increasing due to the number of people living in cities. Risk is also increasingly unpredictable due to the complexity of city systems and the uncertainty associated with many hazards – notably climate change. Risk assessments and measures to reduce specific foreseeable risks will continue to play an important role in urban planning. In addition, cities need to ensure that their development strategies and investment decisions enhance, rather than undermine, the city’s resilience. If governments, donors, investors, policy-makers, and the private sector are to collectively support and foster more resilient cities, there needs to be a common understanding of what constitutes a resilient city and how it can be achieved. The City Resilience Framework responds to this challenge by providing an accessible, evidence-based articulation of city resilience. Over the coming months, it will be further developed to create the City Resilience Index, which will introduce variables that provide a robust basis for measuring resilience at the city scale. The primary audience for this tool is municipal governments. But, the framework, indicators and variables are also intended to support dialogue between other stakeholders who contribute to building more resilient cities globally.What is city resilience?Definition | City resilience describesthe capacity of cities to function, so that the people living and working in cities– particularly the poor and vulnerable – survive and thrive no matter what stresses or shocks they encounter.Resilience is a term that emerged from the field of ecology in the 1970s, to describe the capacity of a system to maintainor recover functionality in the event of disruption or disturbance. It is applicableto cities because they are complex systems that are constantly adapting to changing circumstances. The notion of a resilient city becomes conceptually relevant when chronic stresses or sudden shocks threaten widespread disruption or the collapse of physical or social systems. The conceptual limitation of resilience is that it does not necessarily account for the power dynamics that are inherent in the way cities function and cope with disruptions.In the context of cities, resilience has helped to bridge the gap between disaster risk reduction and climate change adaptation.It moves away from traditional disaster risk management, which is founded on risk assessments that relate to specific hazards. Instead, it accepts the possibility that a wide range of disruptive events – both stresses and shocks – may occur but are not necessarily predictable. Resilience focuses on enhancing the performance of a system in the face of multiple hazards, rather than preventing or mitigating the loss of assets due to specific events.“By April 2014, to articulateurban resilience in a measurable,evidence-based and accessibleway that can inform urbanplanning, practice, and investmentpatterns which better enableurban communities (e.g. poor andvulnerable, businesses, coastal) tosurvive and thrive multiple shocksand stresses.”Opportunity statement (RockefellerGrantee Workshop, New York City,February 2013)(Image opposite)Area of redevelopment in the Silo District, Cape Town.3City Resilience Framework - The Rockefeller Foundation | Arup4City Resilience Framework - The Rockefeller Foundation | ArupLearning from cities Fieldwork | To ensure the framework is widely applicable and grounded in the experiences of cities, the second stage of research involved fieldwork in six cities: Cali, Colombia; Concepción, Chile; New Orleans, USA; Cape Town, South Africa; Surat, India; and Semarang, Indonesia. These cities were selected as they had either recently experienced a major shock or are suffering chronic stresses, and as a group are geographically diverse. The primary purpose of the fieldwork was to understand what contributes to resilience in cities, and how resilience is understood from the perspective of different city stakeholder groups in different contexts. In each city, we carried out workshops, focus groups and key informant interviews with people from the municipal government, utility providers, business and civil society. Across the six cities, we collected data from 450 consultees and identified 1546 factors. Factors are defined as things (physical) or practices/procedures or behaviours (non-physical) that, in the opinion of the consultees, contribute to the resilience of their cities. A detailed analysis of the factors identified 12 key themes: essential needs; health management; livelihood support; law enforcement; social harmonisation; information and knowledge management; capacity and coordination; critical infrastructure management; environmental management; urban strategy and planning; economic sustainability; accessibility. These themes represent what the city stakeholders perceived to be the key city functions relevant to improving resilience. They map very closely to the functions that were derived from the desk-top analysis, with the following exceptions:Infrastructure + environment | Physical assets were least mentioned by consultees in the field, whereas they feature very strongly in the literature review. In the fieldwork research, emphasis was placed on proactive management and maintenance of infrastructure and the environment, rather CaliConcepción© Municipality of Concepción New Orleans Semarang Surat Learning from literatureApproaches | V arious approaches have been taken to framing or assessing resilience. They focus either on urban assets or systems, and, to varying degrees, consider man-made infrastructure, the natural environment, urban management and human behaviour. Asset-based approaches tend to focus on physical assets, rather than considering intangible assets that influence human behaviour, such as culture, social networks and knowledge. They neglect the role that assets play in city systems, and, therefore, overlook the importance of assets outside the city boundary; for example, a reservoir that may be a critical part of the water supply or flood management system.System-based approaches align more closely with the concept of resilience, and the long-standing notion of cities as ‘systems of systems’. Social systems determine human behaviour, which is also influenced by physical systems in the urban environment. V arious approaches exist, but they mostly examine the resilience of individual sub-systems rather than attempting to consider the resilience of the city as a system in itself. This promotes a sectoral approach and means that interdependencies between different systems at different scales, and the governing structures that influence the way systems work, are not easily considered.Finally, empirical evidence throughout the literature suggests that urban systems that exhibit particular qualities (or characteristics) are more likely to be resilient. The seven qualities summarised opposite are derived from published literature, including the set of characteristics developed previously by Arup and the Institute for Social and Environmental Transition, as used by the Asian Cities Climate Change Resilience Network. These qualities apply at a city scale and to individual systems.We concluded that what was missing is a comprehensive, holistic framework that combines the physical aspects of cities with the less tangible aspects associated with human behaviour; that is relevant in the context of economic, physical and social disruption; and that applies at the city scale rather than to individual systems within a city. Finally, it needs to incorporate the qualities that describe a resilient city (or system).Learning from case studies Functions and failure | A performance-based approach, which defines resilience in terms of a city’s ability to fulfil and sustain its core functions, offers a more comprehensive and holistic approach. As a city’s functions rely on a combination of assets, systems, practices and actions undertaken by multiple actors, a performance-based approach has greater potential to address questions of interdependency, power dynamics and scale.Based on the literature review, a draft hypothesis was developed which proposed that urban resilience could be framed in relation to seven critical functions of a city. This was tested through a desk-based analysis of the ‘factors’ of resilience identified from more than 150 sources, which examined cities experiencing shocks or stresses, together with recent guidance on urban resilience. This analysis resulted in a refined list of eight city functions that are critical to resilience. The functions propose that a resilient city: delivers basic needs; safeguards human life; protects, maintains and enhances assets; facilitates human relationships and identity; promotes knowledge; defends the rule of law, justice and equity; supports livelihoods; stimulates economic prosperity. The city’s ability to perform these functions determines whether the city is resilient or not. Resilience could be perceived as good health, a safe environment, social harmony and prosperity. Conversely, a city that is not resilient would be identified by ill-health or insecurity, an unsafe environment, conflict and deprivation.Cape TownEvery city is unique. The wayresilience manifests itself playsout differently in different places.The City Resilience Frameworkprovides a lens through whichthe complexity of cities and thenumerous factors that contributeto a city’s resilience can beunderstood. It comprises 12 keyindicators that describe thefundamental attributes of a resilientcity.City Resilience FrameworkA resilient city is a city where there is or are…1. Minimal human vulnerability Indicated by the extent to which everyone’s basic needs are met.2. Diverse livelihoods and employment Facilitated by access to finance, ability to accrue savings, skills training, business support and social welfare.3. Adequate safeguards to human life and healthRelying on integrated health facilitiesand services, and responsive emergency services.4. Collective identity and mutual support Observed as active community engagement, strong social networks and social integration.5. Social stability and security Including law enforcement, crime prevention, justice, and emergency management.6. Availability of financial resources and contingency fundsObserved as sound financial management, diverse revenue streams, the ability to attract business investment, adequate investment, and emergency funds. 7. Reduced physical exposure and vulnerabilityIndicated by environmental stewardship; appropriate infrastructure; effective landuse planning; and enforcement of planning regulations.8. Continuity of critical services Indicated by diverse provision and active management; maintenance of ecosystems and infrastructure; and contingency planning9. Reliable communications and mobility Indicated by diverse and affordable multi-modal transport systems and information and communication technology (ICT) networks; and contingency planning.10. Effective leadership and management Involving government, business and civil society, and indicated by trusted individuals; multi-stakeholder consultation; and evidence-based decision-making.11. Empowered stakeholdersIndicated by education for all, and accessto up-to-date information and knowledgeto enable people and organisations to take appropriate action.12. Integrated development planning Indicated by the presence of a city vision; an integrated development strategy; and plans that are regularly reviewed and updated by cross-departmental working groups.(Image across)View of Concepción, Chile.7City Resilience Framework - The Rockefeller Foundation | Arup8City Resilience Framework - The Rockefeller Foundation | Arup Qualities The indicators are complemented by qualities that distinguish a resilient city from one that is simply liveable, sustainable or prosperous. These qualities are considered to be important in preventing breakdown or failure; or enabling appropriate and timely action to be taken. They can be observed in relation to the various assets, systems, behaviours and practices that collectively contribute to achieving the 12 outcomes (or indicators). For example, health services that are flexible can reallocate staff to deal with an outbreak of disease. Protective infrastructure that is robust will not fail catastrophically when design thresholds are exceeded. Energy systems with redundancy can accommodate surges in demand or disruption to supply networks. Planning processes that are reflective are better placed to respond to changing circumstances. Families that are resourceful will have put aside savings or invested in insurance. Early warning systems that are inclusive will minimise loss of life and property. City resilience is complex. The three layers of the City Resilience Framework – categories, indicators and qualities – each contribute to a richer articulation of resilience. The framework can be used to facilitate a common understanding of resilience amongst diverse stakeholders. It can also be used to identify where there are critical gaps, where action and investment to build resilience will be most effective, or where deeper analysis or understanding is required. The final layer will be the variables and metrics that result in the City Resilience Index. This will enable cities to carry out an objective assessment of their resilience and measure progress against an initial baseline. IndicatorsCategoriesIndicators The relative importance of the 12 indicators is likely to depend on the urban context and the challenges a city faces. However, our research tells us that, generally, these factors are what matter most when a city faces a wide range of chronic problems or a sudden catastrophe. They represent the backbone of a resilient city. They are what enable people to survive and thrive and businesses to prosper despite adverse circumstances.The twelve indicators provide a holistic articulation of resilience which equates to the elements of a city’s immune system. A weakness in one area may compromise the city’s resilience overall, unless it is compensated for by strength elsewhere. In Guangzhou, China, public squares were redesigned to encourage social interaction between migrant workers as part of an integrated approach to urban planning. In Surat, India, there has been substantial investment in health services to offset the lack of family support and social networks among migrant workers.The indicators are performance indicators; they describe the outcome of actions to build resilience, not the actions themselves. This acknowledges that resilience results from individual and collective action at various levels, delivered by multiple stakeholders ranging from households to municipal government. In Cape Town, South Africa, emergency response in some townships has fallen to community groups, as the city police force is unwilling to operate in these areas due to concerns for their safety. In the Philippines, the efficacy of a community-based early warning system in Metro Manila has been strengthened through access to data and knowledge as a result of a partnership between a local non-governmental agency and the university. QualitiesCategoriesThe 12 indicators fall into four categories: the health and wellbeing of individuals (people); infrastructure & environment (place); economy and society (organisation); and, finally, leadership and strategy (knowledge). For each, it is possible to envisage a best case which represents a resilient city, and a worst case which equates to breakdown or collapse. A city characterised by poverty, social conflict, poor quality infrastructure and weak governance is not resilient. This is evident in Port au Prince, Haiti, where recovery following the devastation caused by an earthquake on 12 January 2010 has proven particularly challenging.The categories can be used to explain New York City’s resilience, as demonstrated following Superstorm Sandy in 2012, and, previously, after the 9/11 terrorist attack in 2001. This was due to the city’s relative prosperity, but also to collective identity and effective city leadership. These factors meant that people were willing to help each other and unite around the common goal of getting the city back to normal as quickly as possible. Emergency plans were in place that meant that urban systems and services were rapidly reinstated and civil order was maintained.Wealthier cities are not necessarily more resilient, as demonstrated by the decline of the US city of Detroit, which became overly dependent on a single industry, or the flooding which brought Bangkok, Thailand, to a standstill in 2010, affecting supply chains globally. Conversely, relatively poor cities can make choices that build resilience. Gorakhpur, India, is working to build resilience at the ward level in response to annual waterlogging in poorer parts of the city. By improving solid waste management practices to unblock drains, and increasing drainage of waterlogged areas, the city has reduced incidences of diseases such as malaria and Japanese encephalitis, which are spread by vectors that breed in waterlogged areas.“Resilience is based on the shifting relationship between scales, and between autonomy on the one hand and connectivity on the other.”Allan, P. & Bryant, M. (2011) ‘Resilience as a framework for urbanism and recovery’. Journal of Landscape Architecture 6(2), p. 439City Resilience Framework - The Rockefeller Foundation | Arup1. Minimal human vulnerability This relates to the extent to which everyone’s basic needs are met. Minimising underlying human vulnerabilities enables individuals and households to achieve a standard of living which goes beyond mere survival. A basic level of wellbeing also allows people to deal with unforeseen circumstances. This is only possible once their physiological needs are met through a basic level of provision of food, water and sanitation, energy and shelter.The focus of this indicator is on providing an adequate and dependable supply of essential services to a city’s whole population. Access to shelter and food – particularly for vulnerable groups – as well as suffi cient, safe, and reliable citywide water, sanitation and energy networks are key to achieving this goal. Evidence from cities suggests that the affordability of these services is also critical to ensuring the whole population has daily access, including during times of disruption. The robustness of essential city networks becomes particularly important in severe environmental events. For example: electricity power lines may be damaged by storms.If failure occurs, resourceful city utility companies are able to respond quickly in line with coordinated and pre-prepared emergency plans. Inclusive plans are also essentialto ensure that all communities receive a minimum supply of basic assets, notably water and food, particularly in extreme circumstances.Specifi c sub-indicators that underpin this indicator area include: Food; Water and sanitation; Energy; Housing.2. Diverse livelihoods andemploymentThis is facilitated by access to fi nance,ability to accrue savings, skills training,business support, and social welfare.Diverse livelihood opportunities andsupport mechanisms allow citizens toproactively respond to changing conditionswithin their city without undermining theirwellbeing. Access to fi nance, skills trainingand business support enables individualsto pursue a range of options to secure thecritical assets necessary to meet their basicneeds. Long-term, secure livelihoods allowpeople to accrue personal savings that willsupport their development, as well as theirsurvival during times of crisis.Mechanisms through which diverselivelihood and employment opportunitiescan be generated include training and skillsdevelopment, microfi nance, incentiveand innovation programmes, as well asa living wage. Financial resources forbusiness development and incentivesfor innovation allow individuals to seekdiverse employment options during times ofeconomic constraint or change. Contingencymeasures, such as insurance and socialwelfare, contribute to supporting householdsthrough challenging circumstances.An inclusive approach to livelihoodsensures that all citizens in a city haveunrestricted access to legitimateoccupations, regardless of race, ethnicity,gender or sexual orientation. A range ofdiverse (redundant) small, medium andlarge businesses in different economicsectors helps people to access jobopportunities, even during challengingmacro-economic circumstances. In thelong term, microfi nance, savings, training,business support and social welfare form asafety net that enables people to be fl exibleduring times of stress.Specifi c sub-indicators that underpinthis indicator area include: Livelihoodopportunities; Skills and training;Development and innovation; Access tofi nancial assistance.3. Adequate safeguards to humanlife and healthThis relies on integrated health facilitiesand services, and responsive emergencyservices.Health systems are critical to the day-to-day prevention of illness and the spread ofdisease, as well as protecting the populationduring emergencies. They comprise adiverse suite of practices and infrastructure,which help to maintain public health andtreat chronic and acute health problems.Health services encompass a variety ofpractices, including: education; sanitation;epidemiological surveillance; vaccination;and provision of healthcare services. Theseare focused on ensuring both physical andmental health. Accessible and affordableday-to-day individual healthcare, as well asappropriate population-based interventions(i.e. targeted at the community or city level),are key features of a functioning city healthsystem.Measures to address injuries and addictionare also important to reduce the burdenof ill-health in urban settings. Effective,inclusive and well-prepared medical staffand procedures ensure that all individualshave access to health services before, aswell as during, emergencies. Responsiveemergency services provide surge capacityto support peak demand during a crisis.In order to achieve the above, appropriatehealth infrastructure is critical.Refl ective learning and future planningensure that public health practices − suchas prevention through education − areappropriate for the social and physicalcontext of a given city. Services orfacilities that target vulnerable groupsensure that preventive and responsivestrategies are inclusive and able to reachthe entire population. In emergencies, adiverse network of medical practitionersand facilities throughout the city ensuresthe availability of additional resources(redundancy) that can be deployedimmediately wherever they are needed.Specifi c sub-indicators that underpinthis indicator area include: Public healthmanagement; Access to affordablehealth services; Emergency facilities andpractitioners.City Resilience Framework - The Rockefeller Foundation | Arup10。
海洋物种濒临灭绝的现状 考研英语阅读 shifting baseline
海洋物种濒临灭绝的现状考研英语阅读shifting baselineThe Current State of Endangered Marine Species: A Shifting Baseline PerspectiveThe vast expanse of the world's oceans has long been perceived as an endless source of resources, a realm teeming with diverse and resilient life. However, the harsh reality is that many marine species are facing an unprecedented threat of extinction, a crisis that demands urgent attention and concerted action. As we grapple with the shifting baseline syndrome, understanding the current state of endangered marine species and the underlying factors driving their decline becomes crucial for safeguarding the delicate balance of our oceanic ecosystems.One of the primary concerns regarding endangered marine species is the alarming rate at which their populations are dwindling. According to the International Union for Conservation of Nature (IUCN), a staggering 27% of the world's sharks and rays are now threatened with extinction. This includes iconic species such as the great white shark, the hammerhead shark, and the manta ray, all ofwhich play vital roles in maintaining the health and balance of marine ecosystems. The decline of these apex predators can have cascading effects, disrupting the intricate food webs and leading to further imbalances in the delicate web of life beneath the waves.In addition to sharks and rays, numerous other marine species are also facing similar threats. The vaquita, a small porpoise found only in the Gulf of California, is on the brink of extinction, with fewer than 20 individuals remaining. The Hawaiian monk seal, once abundant in the Hawaiian Archipelago, has seen its population plummet to just a few hundred individuals due to a combination of factors, including entanglement in fishing gear, habitat loss, and human disturbance. The plight of these charismatic species serves as a sobering reminder of the fragility of our marine ecosystems and the urgent need for comprehensive conservation efforts.The underlying causes of this marine biodiversity crisis are multifaceted and complex. Overfishing, a persistent and widespread issue, has depleted the populations of many commercially valuable species, often through the use of unsustainable fishing practices. The bycatch of non-target species, such as sea turtles, dolphins, and seabirds, further exacerbates the problem, as these animals are often unintentionally caught and killed in the pursuit of other fisheries.Climate change and ocean acidification pose additional threats tomarine species. Rising sea temperatures and changing ocean currents can disrupt the delicate balance of marine ecosystems, causing shifts in species distribution and altering the availability of critical resources. Ocean acidification, a consequence of increased carbon dioxide absorption by the oceans, can have detrimental effects on organisms with calcium-based structures, such as coral reefs and shellfish, further destabilizing the foundation of marine food webs.Habitat destruction and degradation also contribute significantly to the decline of endangered marine species. Coastal development, pollution, and the destruction of critical habitats like mangrove forests, seagrass beds, and coral reefs can have devastating impacts on the species that rely on these ecosystems for survival. The loss of these vital habitats not only threatens the species that directly depend on them but also disrupts the broader functioning of marine ecosystems.The shifting baseline syndrome, a phenomenon where each generation perceives the current state of the environment as the "normal" or "natural" condition, further complicates the understanding and appreciation of the severity of the marine biodiversity crisis. As successive generations become accustomed to a progressively degraded environment, the baseline for what is considered a healthy, thriving marine ecosystem shifts, making itincreasingly difficult to recognize and address the true scale of the problem.Addressing the plight of endangered marine species requires a multifaceted approach that combines scientific research, effective policies, and collaborative efforts among various stakeholders. Strengthening international treaties and regulations, such as the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), can help curb the illegal trade and exploitation of endangered marine species. Implementing robust fisheries management strategies, including the establishment of marine protected areas and the adoption of sustainable fishing practices, can help rebuild depleted populations and restore the balance of marine ecosystems.Additionally, investing in habitat restoration and conservation initiatives can play a crucial role in safeguarding the critical environments that support endangered marine species. Coral reef restoration projects, mangrove reforestation efforts, and the protection of seagrass beds and other coastal habitats can help mitigate the impacts of habitat loss and degradation.Engaging local communities and indigenous populations in conservation efforts is also essential, as these groups often possess invaluable traditional ecological knowledge and can serve asstewards of the marine environment. Empowering these stakeholders to participate in decision-making processes and to become active agents of change can lead to more effective and sustainable conservation outcomes.Ultimately, addressing the crisis of endangered marine species requires a holistic approach that addresses the multifaceted challenges facing our oceans. By combining scientific research, effective policies, and collaborative efforts, we can work towards a future where the diversity and resilience of marine life are preserved for generations to come. As we confront the shifting baseline syndrome and strive to restore the true abundance and vitality of our oceans, we must recognize the intrinsic value of these ecosystems and the crucial role they play in sustaining life on our planet.。
高二英语生物分类单选题50题
高二英语生物分类单选题50题1. Which of the following belongs to the phylum Arthropoda?A. EarthwormB. StarfishC. ButterflyD. Sponge答案：C。
解析：节肢动物门（Arthropoda）的典型特征包括具有分节的附肢等。
蝴蝶（Butterfly）属于节肢动物门。
蚯蚓（Earthworm）属于环节动物门 Annelida）。
海星 Starfish）属于棘皮动物门Echinodermata）。
海绵 Sponge）属于多孔动物门 Porifera）。
2. The organism which is classified in the class Mammalia should have the following feature:A. Gills for breathingB. Feathers on the bodyC. Hair or fur and produce milk to feed their youngD. Scales on the body答案：C。
解析：哺乳纲（Mammalia）的生物具有毛发或皮毛并且能够产奶哺育幼崽。
用鳃呼吸（Gills for breathing）是鱼类等水生生物的特征，它们属于鱼纲等，不属于哺乳纲。
身上有羽毛（Feathers on the body）是鸟类的特征，鸟类属于鸟纲（Aves）。
身上有鳞片（Scales on the body）是爬行动物等的特征，爬行动物属于爬行纲（Reptilia）。
3. Which kingdom does the mushroom belong to?A. AnimaliaB. PlantaeC. FungiD. Protista答案：C。
解析：蘑菇属于真菌界（Fungi）。
动物界（Animalia）的生物具有能运动、异养等特点。
雅思阅读机经真题解析之南极气候
雅思阅读机经真题解析之南极气候雅思阅读机经真题解析-南极气候Antarctica-in from the cold?A A little over a century ago, men of the ilk of Scott, Shackleton and Mawson battled against Antarctica's blizzards, cold and deprivation. In the name of Empire and in an age of heroic deeds they created an image of Antarctica that was to last well into the 20th century - an image of remoteness, hardship, bleakness and isolation that was the province of only the most courageous of men. The image was one of a place removed from everyday reality, of a place with no apparent value to anyone.B As we enter the 21st century, our perception of Antarctica has changed. Although physically Antarctica is no closer and probably no warmer, and to spend time there still demands a dedication not seen in ordinary life, the continent and its surrounding ocean are increasingly seen to an integral part of Planet Earth, and a key component in the Earth System. Is this because the world seems a little smaller these days, shrunk by TV and tourism, or is it because Antarctica really does occupy a central spot on Earth's mantle? Scientific research during the past half century has revealed - and continues to reveal - that Antarctica's great mass and low temperatureexert a major influence on climate and ocean circulation, factors which influence the lives of millions of people all over the globe.C Antarctica was not always cold. The slow break-up of the super-continent Gondwana with the northward movements of Africa, South America, India and Australia eventually created enough space around Antarctica for the development of an Antarctic Circumpolar Current (ACQ, that flowed from west to east under the influence of the prevailing westerly winds. Antarctica cooled, its vegetation perished, glaciation began and the continent took on its present-day appearance. Today the ice that overlies the bedrock is up to 4km thick, and surface temperatures as low as - 89.2deg C have been recorded. The icy blast that howls over the ice cap and out to sea - the so-called katabatic wind - can reach 300 km/hr, creating fearsome wind-chill effects.D Out of this extreme environment come some powerful forces that reverberate around the world. The Earth's rotation, coupled to the generation of cells of low pressure off the Antarctic coast, would allow Astronauts a view of Antarctica that is as beautiful as it is awesome. Spinning away to the northeast, the cells grow and deepen, whipping up the Southern Ocean into the mountainous seas so respected by mariners. Recent work is showing that the temperature of the ocean may be a better predictor of rainfall in Australia than is the pressure difference between Darwin and Tahiti - the Southern Oscillation Index. By receiving moreaccurate predictions, graziers in northern Queensland are able to avoid overstocking in years when rainfall will be poor. Not only does this limit their losses but it prevents serious pasture degradation that may take decades to repair. CSIRO is developing this as a prototype forecasting system, but we can confidently predict that as we know more about the Antarctic and Southern Ocean we will be able to enhance and extend our predictive ability.E The ocean's surface temperature results from the interplay between doep- wa,ter temperature, air temperature and ice. Each winter between 4 and 19 million square km of sea ice form, locking up huge quantities of heat close to the continent.Only now can we start to unravel the influence of sea ice on the weather that is experienced in southern Australia. But in another way the extent of sea ice extends its influence far beyond V Antarctica. Antarctic krill - the small shrimp-like crustaceans that are the staple diet for baleen whales, penguins, some seals, flighted sea birds and many fish - breed well in years when sea ice is extensive and poorly when it is not. Mary species of baleen whales and flighted sea birds migrate between the hemispheres and when the krill are less abundant they do not thrive.F The circulatory system of the world's oceans is like a huge conveyor belt, moving water and dissolved minerals and nutrients from one hemisphere to the other, and from the ocean's abyssal depths to thesurface. The ACC is the longest current in the world, and has the largest flow. Through it, the deep flows of the Atlantic, Indian and Pacific Oceans are joined to form part of a single global thermohalinc circulation. During winter, the howling katabatics sometimes scour the ice off patches of the sea's surface leaving Large ice- locked lagoons, or 'polynyas'. Recent research has shown that as fresh sea ice forms, it is continuously stripped away by the wind and may be blown up to 90km in a single day. Since only fresh water freezes into ice, the water that remains bccom.cs increasingly salty and dense, sinking until it spills over the continental shelf. Cold water carries more oxygen than warm water, so when it rises, well into the northern hemisphere, it reoxygenates and revitalises the ocean. The state of the northern oceans, and their biological productivity, owe much to what happens in the Antarctic.Question 14-18The reading Passage has ten paragraphs A-J.Which paragraph contains the following information?Write the correct letter A-F, in boxes 14-18 on your answer sheet.14. introduction of a millman under awards15. the definition of an important geographical term16. a rival against Harrison’s invention emerged17. problems of sailor encountered in identifying the postion on the sea18. economic assist from another counterpartQuestion 19-21SummaryPlease match the natural phenomenon with correct determined factor Choose the correct answer from the box; Write the correct letter A-F in boxes 19-21 on your answer sheet.19. Globally, mass Antarctica’s size and _________ influence the climate change.20. __________ contributory to western wind.21. Southern Oscillation Index based on air pressure can predict__________ in Australia.A Antarctic Circumpolar Current (ACC)B katabatic windsC rainfallD temperatureE glaciersF pressureQuestion 22-26Choose the correct letter, A,B,C or D.Write your answers in boxes 22-26 on you answer sheet.22 In the paragraph B, the author want to tell which of thefollowing truth about Antarctic?A To show Antarctica has been a central topic of global warming in Mass mediaB To illustrate its huge see ice brings food to million lives to places in the worldC To show it is the heart and its significance to the global climate and currentD To illustrate it locates in the central spot on Earth geographically23 Why do Australian farmers Keep an eye on the Antarctic ocean temperature ?A Help farmers reduce their economic or ecological lossesB Retrieve grassland decreased in the overgrazing processC Prevent animal from dyingD A cell provides fertilizer for the grassland24 What is the final effect of katabatic winds?A Increase the moving speed of ocean currentB Increase salt level near ocean surfaceC Bring fresh ice into southern oceansD Pile up the mountainous ice cap respected by mariners25 The break of the continental shelf is due to theA Salt and density increaseB Salt and density decreaseC global warming resulting a rising temperatureD fresh ice melting into ocean water26 The decrease in number of Whales and seabirds is due toA killers whales arc more active aroundB Sea birds are affected by high sea level saltyC less sea ice reduces productivity of food sourceD seals fail to reproduce babies篇章结构体裁说明文题目南极洲的自然环境及其对全球气候和水循环等的影响结构A段：之前的南极洲被人类遗忘，毫无价值B段：21世纪，人类对南极洲有了新的认识，发现它对气候，海洋环流有重大影响C段：南极洲气候变化是如何形成的D段：关于南极洲气候的预测对澳大利亚农业的影响E段：南澳大利亚的海冰对海洋生态（动物）的影响F段：南极海冰为北半球带来积极影响G段：南极洲的强大影响力得到人类肯定试题分析Question14-18题目类型：段落信息配对题Question19-21题目类型：填空题Question22-26题目类型：选择题题号定位词文中对应点题目解析14Weather prediction, agricultureD段第五，六句D段第五六两句提到“通过接收更为准确的预测，放牧人能够·······。
Global sensitivity analysis
GLOBAL SENSITIVITY ANALYSISGlobal sensitivity analysis is the study of how the uncertainty in the output of a model (numerical or otherwise) can be apportioned to different sources of uncertainty in the model input”. Global could be an unnecessary specification here, were it not for the fact that most analysis met in the literature are local or one-factor-at-a-time.All models have use for global sensitivity analysis. Applications worked out by the Joint Research Centre group for Applied Statistics include: Atmospheric chemistry, transport emission modelling, fish population dynamics, composite indicators, hydrocarbon exploration models, macroeconomic modelling, radioactive waste management.Prescriptions have been issued for global sensitivity analysis of models when these used for policy analysis. In Europe, the European Commission recommends sensitivity analysis in the context of the extended impact assessment guidelines and handbook (2002). Similar recommendation in the United States EPA’s White Paper o n model use acceptability (1999).The EC handbook for extended impact assessment, a working document by the European Commission, 2002, states: “A good sensitivity analysis should conduct analyses over the full range of plausible values of key parameters and their interactions, to assess how impacts change in response to changes in key parameters”.The EPA paper (1999) is less prescriptive, but insists on the need for uncertainty and sensitivity analysis.We list below what are the desirable properties of an ideal global sensitivity analysis method.1. Cope with the influence of scale and shape. The influence of the input should incorporate theeffect of the range of input variation and the form of its probability density function (pdf). It matters whether the pdf of an input factor is uniform or normal, and what are the distribution parameters.2. Include multidimensional averaging. In a local approach to SA one computes partialderivatives, as discussed above. This is the effect of the variation of a factor when all othersare kept constant at the central (nominal) value. A global method should instead evaluate the effect of a factor while all others are varying as well.3. Be model independent. The method should work regardless of the additivity or linearity ofthe model. A global sensitivity measure must be able to appreciate the so-called interaction effect, especially important for non-linear, non-additive models. These arise when the effect of changing two factors is different from the sum of their individual effects.4. Be able to treat grouped factors as if they were single factors. This property of synthesis isessential for the agility of the interpretation of the results. One would not want to beconfronted with a SA made of dense tables of sensitivity measures.A few words about the output Y of interest. In our experience, the target of interest should not be the model output per se, but the question that the model has been called to answer. To make an example, if a model predicts contaminant distribution over space and time, it is the total areawhere a given threshold is exceeded at a given time which would play as output of interest, or the total health effects per time unit.One should seek from the analyses conclusions of relevance to the question put to the model,as opposed to relevant to the model, e.g.Uncertainty in emission inventories [in transport] are driven by variability in driving habits morethan from uncertainty in engine emission data.In transport with chemical reaction problems, uncertainty in the chemistry dominates over uncertainty in the inventories.Engineered barrier count less than geological barriers in radioactive waste migration.This remark on the output of interest clearly applies to model use, not to model building, where the analyst might have interest in studying a variety of intermediate outputs.Suggested ReferencesCampolongo, F., Saltelli A,. Jensen, N.R., Wilson, J., and Hjorth, J., 1999a, The role of multiphase chemistry in the oxidation of dimethylsulphide (DMS). A latitude dependent analysis, Journal of Atmospheric Chemistry, 32, 327-356.Campolongo, F., Tarantola, S., and Saltelli, A., 1999b, Tackling quantitatively large dimensionality problems, Computer Physics Communications, 117, 75-85.Crosetto, M. and Tarantola, S., 2001 Uncertainty and Sensitivity Analysis: Tools for GIS-based Model Implementation, International Journal of Geographic Information Science, 154, 415-437.EC, 2000, European Commission’s Communication on Extended Impact Assessment Brussels, 05/06/2002 COM(2002) 276 final. Guidelines for implementing the directive are available at the Governance page of the EC, http://europa.eu.int/comm/governance/docs/index_en.htm.EPA, 1999, The US Environmental Protection Agency Science Policy Council, White Paper on the Nature and Scope of Issues on Adoption of Model Use Acceptability Guidance,/osp/crem/library/whitepaper_1999.pdf.Ratto, M., Tarantola, S. and A. Saltelli 2001, Sensitivity analysis in model calibration:GSA-GLUE approach, Computer Physics Communications, 136, 212-224.Saltelli, A., S. Tarantola, K. Chan, 1999, A quantitative, model independent method for global sensitivity analysis of model output, Technometrics, 41 (1), 39-56.Saltelli, A., K. Chan and M. Scott, Eds., 2000, Handbook of sensitivity analysis, John Wiley & Sons publishers, Probability and Statistics series.Saltelli, A., 1999, Sensitivity analysis. Could better methods be used?, Journal of Geophysical Research, 104(D3), 3789-3793. N.B. see also Errata Corrige for a table’s error on the same journal, 1999, 104(D19), 24,013.Saltelli, A. (2002). Making best use of model valuations to compute sensitivity indices. Computer Physics Communications, 145, 280-297.Saltelli, A., Tarantola, S. Campolongo, F., 2000, Sensitivity analysis as an ingredient of modelling, Statistical Science, 15(4), 377-395.Saltelli A. Tarantola S., 2002, On the relative importance of input factors in mathematical models: safety assessment for nuclear waste disposal, Journal of American Statistical Association, 97 (459), 702-709.Saltelli A. Tarantola S., 2004, Campolongo, F. and Ratto, M., Sensitivity Analysis in Practice. A Guide to Assessing Scientific Models, John Wiley & Sons publishers, Probability and Statistics series, 2003 (to appear).Tarantola, S., J. Jesinghaus, M. Puolamaa, 2000, Global sensitivity analysis: a quality assurance tool in environmental policy modelling, in Saltelli, et al. (Eds) 2000, 385-397.Tarantola S., Saisana M., Saltelli A., Schmiedel F. and N. Leapman (2002) Statistical techniques and participatory approaches for the composition of the European Internal Market Index1992-2001, European Commission, EUR 20547 EN.MONTE CARLO (OR SAMPLE_BASED) ANALYSISMonte Carlo (MC) analysis is based on performing multiple evaluations with randomly selected model input, and then using the results of these evaluations to determine both uncertainty in model predictions and apportioning to the input factors their contribution to this uncertainty. A MC analysis involves the selection of ranges and distributions for each input factor; generation of a sample from the ranges and distributions specified in the first step; evaluation of the model for each element of the sample; uncertainty analysis and sensitivity analysis.Various sampling procedures are used in MC studies. Among those are: random sampling, stratified sampling (including latin hypercube sampling), and quasi-random sampling.Sensitivity measures based on the MC approach include regression-based measures (Standardised Regression Coefficients (SRC), Partial Correlation Coefficients (PCC), Standardised Rank Regression Coefficients (SRRC), Partial Rank Correlation Coefficients (PRCC)).Suggested references:Helton JC, FJ Davis (2000) Sampling Based Methods. Chapter 6 in Mathematical and Statistical Methods for Sensitivity Analysis of Model Output. Edited by A. Saltelli, K. Chan, and M. Scott, John Wiley and Sons.Helton JC (1993) Uncertainty and sensitivity analysis techniques for use in performance assessment for radioactive waste disposal. Reliability Engineering and System Safety, 42,327-367.RESPONSE SURFACE METHODOLOGYThis procedure is based on the development of a response surface approximation to the model under consideration. This approximation is then used as a surrogate for the original model in uncertainty and sensitivity analysis.The analysis involves the selection of ranges and distributions for each input factor, the development of an experimental design defining the combinations of factor values on which evaluate the model, evaluations of the model, construction of a response surface approximation to the original model, uncertainty analysis and sensitivity analysis.Different types of experimental designs are available to select the points at which evaluate the model. The choice of the design points depend on a several factors: the number of independent variables under consideration, the computational effort needed for each model evaluation, the presence of quadratic or higher order effects, the importance of variable interactions.Sensitivity measures for the input factors are derived from the constructed response surface. This surface plays the same role in a response surface methodology as the Taylor series in a differential analysis.SCREENING DESIGNSFactors screening may be useful as a first step when dealing with a model containing a large number of input factors (hundreds). By input factor we mean any quantity that can be changed in the model prior to its execution. This can be a model parameter, or an input variable, or a model scenario. Often, only a few of the input factors and groupings of factors, have a significant effect on the model output.Screening experiments are used to identify the subset of factors that controls most of the output variability with a relatively low computational effort. As a drawback, these economical methods tend to provide qualitative sensitivity measures, i.e. they rank the input factors in order of importance, but do not quantify how much a given factor is more important than another.Typical screening designs are one-at-a-time (OAT) experiments, in which the impact of changing the values of each of the chosen factors is evaluated in turn. Although simple, easy to implement, and computationally cheap, the OAT methods have a limitation in that they do not enable estimation of interactions among factors and usually provide a sensitivity measure that is local (around a given point of the input space).An OAT design that is not dependent on the choice of the specific point in the input space is that proposed by Morris.Alternative approaches to the problem of screening include the design of Cotter, the Iterated Fractional Factorial Designs (IFFDs) introduced by Andres and Hajas, the sequential bifurcation method proposed by Bettonvil; and the method proposed by Morris, that still being an OAT experiment covers the whole input factor space.Suggested references:F. Campolongo, J. Kleijnen, and T. Andres, 2000, Screening methods in Sensitivity Analysis. Chapter 4 in Sensitivity Analysis, A. Saltelli, K. Chan, and M. Scott, Eds. John Wiley and Sons Publishers.Handbook of Simulation, Jerry Banks Editor, Wiley, New York, 1998.W. J.Welch, R. J.Buck, J. Sacks, H. P. Wynn, T. J. Mitchell , and M. D. Morris, 1992. Screening, predicting, and computer experiments. Technometrics, 34(1), 15-47.Campolongo, F., Saltelli A,. Jensen, N.R., Wilson, J., and Hjorth, J., 1999a, The role of multiphase chemistry in the oxidation of dimethylsulphide (DMS). A latitude dependent analysis, Journal of Atmospheric Chemistry, 32, 327-356.Campolongo, F., Tarantola, S., and Saltelli, A., 1999b, Tackling quantitatively large dimensionality problems, Computer Physics Communications, 117, 75-85.LOCAL - DIFFERENTIAL ANALYSISLocal SA investigates the impact of the input factors on the model locally, i.e. at some fixed point in the space of the input factors. Local SA is usually carried out by computing partial derivatives of the output functions with respect to the input variables (differential analysis). In order to compute the derivative numerically, the input parameters are varied within a small interval around a nominal value. The interval is not related to our degree of knowledge of the variables and is usually the same for all of the variables.One shortcoming of the linear sensitivity approach is that it is not possible to assess effectively the impact of possible differences in the scale of variation of the input variables, unless the model itself is linear. When significant uncertainty exists in the input parameters, the linear sensitivities alone are not likely to provide a reliable estimator of the output uncertainty in the model. When the model is non-linear and various input variables are affected by uncertainties of different orders of magnitude a global sensitivity method should be used.Differential analysis techniques are based on the use of a Taylor series to approximate the model under consideration. Once constructed, this series can be used as a surrogate for the original model in analytical uncertainty and sensitivity studies.A differential analysis involves four steps:（1）base values and ranges are selected for each input factor;（2）a Taylor series approximation to the output is developed around the base values for the inputs;（3）variance propagation techniques are used to estimate the uncertainty in the output in terms of its expected value and its variance;（4）the Taylor series approximation is used to estimate the importance of individual input factors.In the fourth step, there are different ways of measuring the importance of the input factors. For example normalised partial derivatives, in the first order Taylor series approximation, can measurethe effect on the solution that results from perturbing an input factor by a fixed fraction of its base value.One problem arising in a differential analysis is the determination of an appropriate order for the Taylor series approximation. Estimates for expected value and variance, in the third step, vary according to the order of approximation.Differential analysis methods have been used extensively in chemistry in a variety of applications, such as the solution of inverse problems, where they have proven their worth. Nevertheless, the use of global methods, possibly quantitative, should be preferred to derivative-based SA for all problem settings where finite parameter variations are involved, unless the model is known to be linear or the range of variation is small.Suggested references:T. Turanyi, and H. Rabitz. Local methods and their applications. Chapter 5 in Mathematical and Statistical Methods for Sensitivity Analysis of Model Output. Edited by A. Saltelli, K. Chan, and M. Scott, to be published by John Wiley and Sons.T. Turanyi, 1990. Reduction of large reaction mechanisms. New J. Chem. 14, 795-803.FORM-SORMFORM and SORM are useful methods when the analyst is not interested in the magnitude of Y (and hence its potential variation) but in the probability of Y exceeding some critical value. The constraint (Y-Y crit < 0) determines a hyper-surface in the space of the input factors, X. The minimum distance between some design point for X and the hyper-surface is the quantity of interest.Let B denote such a minimum distance for some assigned joint distribution of the input X. In these settings one can chose as sensitivity measure the derivative of B with respect to the input factors. Such a quantity should not be confused with the local derivative of Y with respect to the inputs, as the action of taking the minimum of B over the hyper-space of X introduces an element ofprobabilistic weighting. The First Order Reliability Method (FORM) offers such a probabilistic measure. It gives an estimate of how much a given input factor may drive the risk (probability of failure) of the system.Suggested references:J. Cawlfield. Reliability Algorithms (FORM and SORM). Chapter 7 in Mathematical and Statistical Methods for Sensitivity Analysis of Model Output. Edited by A. Saltelli, K. Chan, and M. Scott, to be published by John Wiley and Sons.。
2024年教师资格(中学)-英语学科知识与教学能力(初中)考试历年真题摘选附带答案
2024年教师资格（中学）-英语学科知识与教学能力（初中）考试历年真题摘选附带答案第1卷一.全考点押密题库(共100题)1.(单项选择题)(每题2.00 分) Language is a tool of communication. The symbol “Highway Closed” on a highway serves→ ←.A. an expressive functionB. an informative functionC. a performative functionD. a persuasive function2.(单项选择题)(每题 2.00 分) I’ve loved my mother's desk since I was just tall enough to see above the top of it as mother sat writing letters. Standing by her chair, looking at the ink bottle, pens, and white paper, I decided that the act of writing must be the most wonderful thing in the world.Years later, during her final illness, mother kept different things for my sister and brother.“But the desk.” she’d said again, “It's for Elizabeth.”I never saw her angry, never saw her cry. I knew she loved me; she showed it in action. But as a young girl, I wanted heart-to-heart talks between mother and daughter.They never happened. And a gulf opened between us. I was “too emotional”. But she lived on the surface”.As years passed I had my own family. I loved my mother and thanked her for our happy family.I wrote to her in careful words and asked her to let me know in any way she chose that she did forgive me.I posted the letter and waited for her answer.None came.My hope turned to disappointment, then little interest and, finally, peace—it seemed that nothing happene I couldn’t be sure that the letter had even got to mother.I only knew that I had written it, and I could stop trying to make her into someone she was not.Now the present of her desk told, as she'd never been able to, that she was pleased thatwriting was my chosen work. I cleaned the desk carefully and found some papers inside—a photo of my father and a one—page letter, folded and refolded many times.Give me an answer, my letter asks, in any way you choose. Mother, you always choose the actthat speaks louder than words. The underlined word “gulf” in the passage means→ ←.A. deep understanding between the old and the youngB. different ideas between the mother and the daughterC. free talks between mother and daughterD. part of the sea going far in land3.(单项选择题)(每题 2.00 分) 40 years ago the idea of disabled people doing sport was never heard of. But when the annual games for the disabled were started at Stoke-Mandeville, Englandin 1948 by Sir Ludwig Guttmann, the situation began to change.Sir Ludwig Guttmann, who had been driven to England in 1939 from Nazi Germany, had been askedby the British government to set up an injuries center at Stoke Mandeville Hospital near London. His ideas about treating injuries included sport for the disabled.In the first games just two teams of injured soldiers took part. The next year, 1949, five teams took part. From those beginnings, things have developed fast Teams now come from abroadto Stoke Mandeville every year. In 1960 the first Olympics for the Disabled were held in Rome, in the same place as the normal Olympic Games. Now, every four years the Olympic Gamesfor the Disabled are held, if possible, in the same place as the normal Olympic Games, althoughthey are organized separately. In other years Games for the Disabled are still held at Stoke Mandeville. In the 1984 wheelchair Olympic Games, 1064 wheelchair athletes from about 40 countries took part. Unfortunately, they were held at Stoke Mandeville and not in Los Angeles, along with the other Olympics.The Games have been a great success in promoting international friendship and understanding,and in proving that being disabled does not mean you can’t enjoy sport. One small sourceof disappointment for those who organize and take part in the games, however, has been the unwillingness of the International Olympic Committee to include disabled events at Olympic Games for the able-bodied. Perhaps a few more years are still needed to convince those fortunate enough not to be disabled that their disabled fellow athletes should not be excluded. The first games for the disabled were held→ ←after Sir Ludwig Guttmann arrived in England.A. 40 yearsB. 21 yearsC. 10 yearsD. 9 years4.(单项选择题)(每题 2.00 分) I’ve loved my mother's desk since I was just tall enough tosee above the top of it as mother sat writing letters. Standing by her chair, looking atthe ink bottle, pens, and white paper, I decided that the act of writing must be the most wonderful thing in the world.Years later, during her final illness, mother kept different things for my sister and brother.“But the desk.” she’d said again, “It's for Elizabeth.”I never saw her angry, never saw her cry. I knew she loved me; she showed it in action. Butas a young girl, I wanted heart-to-heart talks between mother and daughter.They never happened. And a gulf opened between us. I was “too emotional”. But she livedon the surface”.As years passed I had my own family. I loved my mother and thanked her for our happy family.Iwrote to her in careful words and asked her to let me know in any way she chose that she did forgive me.I posted the letter and waited for her answer.None came.My hope turned to disappointment, then little interest and, finally, peace—it seemed that nothing happene I couldn’t be sure that the letter had even got to mother.I only knew thatI had written it, and I could stop trying to make her into someone she was not.Now the present of her desk told, as she'd never been able to, that she was pleased that writing was my chosen work. I cleaned the desk carefully and found some papers inside—a photo of my father and a one—page letter, folded and refolded many times.Give me an answer, my letter asks, in any way you choose. Mother, you always choose the act that speaks louder than words. The passage shows that→ ←.A. mother was cold on the surface but kind in her heart to her daughterB. mother was too serious about everything her daughter had doneC. mother eared much about her daughter in wordsD. mother wrote to her daughter in careful words5.(单项选择题)(每题 2.00 分) In which of the following situations is the teacher playing the role of observer?→ ←A. Giving feedback and dealing with errors.B. Organizing students to do activities by giving instructions.C. Walking around to see how each student performs in group work.D. Offering help to those who need it both in ideas and language.6.(单项选择题)(每题 2.00 分) One evening, while Marcos Ugarte was doing his homework and his father, Eduardo, prepared lesson plans, they heard someone yelling outside. Eduardo, 47, and Marcos, 15, stepped onto the porch of their home in Troutdale, Oregon, and saw a commotion four doors d own, outside the home of their neighbors, the Ma family. “I didn’t think anything was wrong.” Eduardo recalls. “I told Marcos we should give them some privacy.” He headed back inside, but Marcos’s eye was caught by a glow from the Ma house."Dad, the house is on fire!” Marcos cried.Clad only in shorts, the barefoot teen sprinted toward the Ma’s home with his dad. Grandmother Yim Ma, mother Suzanne Ma, and son Nathan Ma were gathered on the front lawn yelling for help. When the Ugartes got there，they saw father Alex Ma stumbling down the stairs, coughing, his face black with soot."Is anyone else in the house?” Eduardo asked."My son!” Alex managed to say, pointing to the second floor Eduardo started up the stairs, but thick, black smoke, swirling ash, and intense heat forced him to his knees. He crawled upstairs and down the hall where Alex said he would find Cody, eight, who had locked himselfin a bedroom.As the fire raged across the hall, Eduardo banged on the bedroom door and tried to turn the doorknob. Cody didn’t respond Eduardo made his way back downstairs.Meanwhile, Marcos saw Yim and Suzanne pulling an aluminum ladder out of the garage. “Cody was standing at the window, screaming for help,"says Marcos, "I knew I had to do something.” He grabbed the ladder, positioned it near the window, and climbed toward the boy.When Marcos reached the window, he pushed the screen into the room and coaxed Cody out. “It’s OK.” Marcos told him. “I‘ve got you.”Holding Cody with one arm. Marcos descended the ladder.When firefighters arrived, plumes of black smoke were billowing from the back of the house as flames engulfed the second floor. Emergency personnel took Cody to a nearby hospital,where he was treated for smoke inhalation and released. No one else was injured. The causeof the blaze is still under investigation."You just don’t see a teenager have that kind of→ composure←," says Mark Maunder, GreshamFire Department battalion chief.The Ma family relocated. The day after the fire, Alex visited Marcos. “Than k you for savingmy son.” Alex said. “You are his hero forever.”What does the underlined word “composure” in the last but one PARAGRAPH mean?→ ←.A. sympathyB. braveryC. calmnessD. warm-heartedness7.(单项选择题)(每题 2.00 分) Resources can be said to be scarce in both an absolute and relative sense: the surface of the Earth is finite, imposing absolute scarcity; but the scarcity that concerns economists is the relative scarcity of resources in different uses. Materials used for one purpose cannot at the same time be used for other purposes, if the quantity of an input is limited, the increased use of it in one manufacturing process must cause it to become less available for other uses.The cost of a product in terms of money may not measure its true cost to society. The truecost of, say, the construction of a supersonic jet is the value of the schools and refrigerators that will never be built as a result. Every act of production uses up someof society's available resources; it means the foregoing of an opportunity to produce something else. In deciding how to use resources most effectively to satisfy the wants ofthe community, this opportunity cost must ultimately be taken into account.In a market economy the price of a good and the quantity supplied depend on the cost of makingit, and that cost, ultimately, is the cost of not making other goods. The market mechanism enforces this relationship. The cost of, say, a pair of shoes is the price of the leather,the labor, the fuel, and other elements used up in producing them. But the price of thesein- puts, in turn, depends on what they can produce elsewhere-if the leather can be usedto produce handbags that are valued highly by consumers, the prices of leather will be bidup correspondingly. W hat does this passage mainly discuss?→ ←A. The scarcity of manufactured goods.B. The value of scarce materials.C. The manufacturing of scarce goods.D. The cost of producing shoes.8.(单项选择题)(每题 2.00 分) Writing exercises like copying, fill-in, completions and transformation are mainly the type of exercises used in→ ←.A. controlled writingB. guided writingC. flee writingD. expressive writing9.(单项选择题)(每题 2.00 分) Which of the following consonants doesn't fall under the same category according to the voicing?________A. [m]B. [b]C. [d]D. [p]10.(单项选择题)(每题 2.00 分) Which of the following is most suitable for the cultivation of linguistic competence?→ ←A. sentence-makingB. cue-card dialogueC. simulated dialogueD. learning syntax11.(单项选择题)(每题 2.00 分) Which of the following sets of phonetic features characterizes the English phoneme [u:]?→ ←A. [high, back, rounded]B. [high, back, unfounded]C. [low, back, rounded]D. [low, front unfounded]12.(单项选择题)(每题 2.00 分) 40 years ago the idea of disabled people doing sport was never heard of. But when the annual games for the disabled were started at Stoke-Mandeville, England in 1948 by Sir Ludwig Guttmann, the situation began to change.Sir Ludwig Guttmann, who had been driven to England in 1939 from Nazi Germany, had been asked by the British government to set up an injuries center at Stoke Mandeville Hospital near London. His ideas about treating injuries included sport for the disabled.In the first games just two teams of injured soldiers took part. The next year, 1949, five teams took part. From those beginnings, things have developed fast Teams now come from abroad to Stoke Mandeville every year. In 1960 the first Olympics for the Disabled were held in Rome, in the same place as the normal Olympic Games. Now, every four years the Olympic Games for the Disabled are held, if possible, in the same place as the normal Olympic Games, although they are organized separately. In other years Games for the Disabled are still held at Stoke Mandeville. In the 1984 wheelchair Olympic Games, 1064 wheelchair athletes from about 40 countries took part. Unfortunately, they were held at Stoke Mandeville and not in Los Angeles, along with the other Olympics.The Games have been a great success in promoting international friendship and understanding, and in proving that being disabled does not mean you can’t enjoy sport. One small source of disappointment for those who organize and take part in the games, however, has been the unwillingness of the International Olympic Committee to include disabled events at Olympic Games for the able-bodied. Perhaps a few more years are still needed to convince those fortunate enough not to be disabled that their disabled fellow athletes should not be excluded. Besides Stoke Mandeville, surely the games for the disabled were once held in→ ←.A. New YorkB. LondonC. RomeD. Los Angeles13.(单项选择题)(每题 2.00 分) —I’m going to study engineering in Peking University tomorrow.—→ ←.A. All the best in your studyB. All the best with your studyC. All the best in your businessD. All the best in your new job14.(单项选择题)(每题 2.00 分) The doctor→ ←a medicine for my headache.A. subscribedB. describedC. prescribedD. inscribed15.(单项选择题)(每题 2.00 分) When a lady customer intends to buy a coat with white stripes,what is she supposed to place an emphasis on if she says to the shop assistant?________A. I'd like a Red coat with .white stripesB. I'd Like a red coat with white stripes.C. I'd like a red coat with White StripesD. I'd like a red Coat with white stripes16.(单项选择题)(每题 2.00 分) What purpose does NOT post-listening activities serve?→ ←A. Helping students relate the text with their personal experience.B. Offering students the opportunities of extending other language skills.C. Practicing students’ ability of matching the pre-listing predictions with contents ofthe text.D. Give the answer directly to students and not to explain.17.(单项选择题)(每题 2.00 分) Which of the following activities can be adopted at thepre-reading stage?→ ←.A. rearranging the materialsB. brainstorming the topicC. writing a summary of the textD. draft framework18.(单项选择题)(每题 2.00 分) Throughout the history of the arts, the nature of creativityhas remained constant to artists. No matter what objects they select, artists are to bringforth new forces and forms that cause change to find poetry where no one has ever seen or experienced it before.Landscape(风景)is another unchanging element of art. It can be found from ancient times through the 17th-century Dutch painters to the 19th-century romanticists and impressionists.In the 1970s, Alfred Leslie, one of the new American realists, continued this practice. Leslie sought out the same place where Thomas Cole, a romanticist, had produced paintings of thesame scene a century and a half before. Unlike Cole who insists on a feeling of lonelinessand the idea of finding peace in nature, Leslie paints what he actually sees. In his paintings,there is no particular change in emotion, and he includes ordinary things like the highwayin the hack: ground. He also takes advantage of the latest developments of color photographyto help both the eye and the memory when he improves his painting back in his workroom. Besides, all art begs the age-old question: What is real? Each generation of artists has shown their understanding of reality in one form or another. The impressionists saw realityin brief emotional effects, the realists in everyday subjects and in forest scenes, and theCro-Magnon cave people in their naturalistic drawings of the animals in the ancient forests.To sum up, understanding reality is a necessary struggle for artists of all periods.Over thousands of years the function of the arts has remained relatively constant. Past or present, Eastern or Western, the arts are a basic part of our immediate experience. Manyand different are the faces of art, and together they express the basic need and hope of human beings. Which of the following is the ma in topic of the passage?→ ←A. History of the arts.B. Basic questions of the arts.C. New developments in the arts.D. Use of modem technology in the arts.19.(单项选择题)(每题 2.00 分) By the end of last year, nearly a million cars→ ←in that auto factory.A. had producedB. had been producedC. would be producedD. were produced20.(单项选择题)(每题 2.00 分) → ←the temperature might drop, coal was prepared for warming.A. To considerB. ConsideredC. ConsideringD. To be considered21.(单项选择题)(每题 2.00 分) → ←a moment and I will go to your rescue.A. Go onB. Hold onC. Move toD. Carry on22.(单项选择题)(每题 2.00 分) The study of language development over a period of time is generally called→ ←linguistics.A. appliedB. synchronicC. comparativeD. diachronic23.(单项选择题)(每题 2.00 分) Which of the following is a slip of tongue?→ ←A. Seeing is believing.B. Where there is smoke, there is fire.C. Where there is life, there is hope.D. Where there is a way, there is a will.24.(单项选择题)(每题 2.00 分) Which of the following statements is NOT a way of presenting new vocabulary?_A. Defining.B. Using real objects.C. Writing a passage by using new words.D. Giving explanations.25.(单项选择题)(每题 2.00 分) For a while, my neighborhood was taken ever by an army of joggers(慢跑者). They were there all the time: early morning, noon, and evening. There were little old ladies in gray sweats, young couples in Adidas shoes, middle-aged men with red faces. "Come on!" My friend Alex encouraged me to join him as he jogged by my house every evening. "You'll feel great."Well, I had nothing against feeling great and if Alex could jog every day, anyone could. So I took up jogging seriously and gave it a good two months of my life, and not a day more. Based on my experience, jogging is the most overvalued form of exercise around, and judging from the number of the people who left our neighborhood jogging army. I’m not alone in my opinion.First of all, jogging is very hard on the body. Your legs and feet a real pounding(追击)ruining down a road for two or three miles. I developed foot, leg, and back problems. Then I readabout a nationally famous jogger who died of a heart attack while jogging, and I had something else to worry about Jogging doesn't kill hundreds of people, but if you have any physical weaknesses, jogging will surely bring them out, as they did with me.Secondly, I got no enjoyment out of jogging. Putting one foot in front of the other for forty-five minutes isn't my idea of fun. Jogging is also a lonely pastime. Some joggers say, "I love being out there with just my thoughts." Well, my thoughts began to bore me, and most of them were on how much my legs hurt.And how could I enjoy something that brought me pain? And that wasn't just the first week, it was practically every day for two months. I never got past the pain level, and pain isn't fun. What a cruel way to do it! So many other exercises, including walking, lead to almost the same results painlessly, so why jog?I don't jog any more, and I don't think I ever will. I’m walking two miles three times a week at a fast pace, and that feels good. I bicycle to work when the weather is good. I'm getting exercise, and I'm enjoying it at the same time. I could never say the same for jogging, and I've found a lot of better ways to stay in shape. What was the writer's attitude towards jogging in the beginning?→ ←A. He felt it was worth a try.B. He was very fond of it.C. He was strongly against it.D. He thought it must be painful.26.(单项选择题)(每题 2.00 分) If a teacher attempts to implement the top-down model to teach listening, he is likely to present_____.A. new words after playing the tapeB. new words before playing the tapeC. background information after playing the tapeD. background information before playing the tape27.(单项选择题)(每题 2.00 分) Trees should only be pruned when there is a good and clear reason for doing so and, fortunately, the number of such reasons is small. Pruning involves the cutting away of overgrown and unwanted branches, and the inexperienced gardener can be encouraged by the thought that more damage results from doing it unnecessarily than from leaving the tree to grow in its own way.First, pruning may be done to make sure that trees have a desired shape or size. The object may be to get a tree of the right height, and at the same time to help the growth of small side branches which will thicken its appearance or give it a special shape. Secondly, pruning may be done to make the tree healthier. You may cut diseased or dead wood, or branches that are rubbing against each other and thus cause wounds. The health of a tree may be encouraged by removing branches that are blocking up the centre and so preventing the free movement of air.One result of pruning is that an open wound is left on the tree and this provides an easy entry for disease, but it is a wound that will heal. Often there is a race between the healing and the disease as to whether the tree will live or die, so that there is a period when the tree is at risk. It should be the aim of every gardener to reduce which has been pruned smooth and clean, for healing will be slowed down by roughness. You should allow the cut surface to dry for a few hurts and then paint it with one of the substances available from garden shops produced especially for this purpose. Pruning is usually without interference from the leaves and also it is very unlikely that the cuts you make will bleed If this does happen, it is, of course, impossible to paint them properly. Pruning should b e done to→ ←.A. make the tree grow tallerB. improve the shape of the treeC. get rid of the small branchesD. make the small branches thicker28.(单项选择题)(每题 2.00 分) Which of the following statements about Audio-lingual Methodis wrong?→ ←A. The method involves giving the learner stimuli in the form of prompts.B. The method involves praising the correct response or publishing incorrect response untilthe right one is given.C. Mother tongue is accepted in the classroom just 8s the target language.D. Emphasis is laid upon using oral language in the classroom; some reading and writing mightbe done as homework.29.(单项选择题)(每题 2.00 分) I’ve loved my mother's desk since I was just tall enough tosee above the top of it as mother sat writing letters. Standing by her chair, looking atthe ink bottle, pens, and white paper, I decided that the act of writing must be the most wonderful thing in the world.Years later, during her final illness, mother kept different things for my sister and brother.“But the desk.” she’d said again, “It's for Elizabeth.”I never saw her angry, never saw her cry. I knew she loved me; she showed it in action. Butas a young girl, I wanted heart-to-heart talks between mother and daughter.They never happened. And a gulf o pened between us. I was “too emotional”. But she livedon the surface”.As years passed I had my own family. I loved my mother and thanked her for our happy family.Iwrote to her in careful words and asked her to let me know in any way she chose that shedid forgive me.I posted the letter and waited for her answer.None came.My hope turned to disappointment, then little interest and, finally, peace—it seemed that nothing happene I couldn’t be sure that the letter had even got to mother.I only knew thatI had written it, and I could stop trying to make her into someone she was not.Now the present of her desk told, as she'd never been able to, that she was pleased that writing was my chosen work. I cleaned the desk carefully and found some papers inside—aphoto of my father and a one—page letter, folded and refolded many times.Give me an answer, my letter asks, in any way you choose. Mother, you always choose the actthat speaks louder than words. What did mother do with her daughter's letter asking forgiveness?A. She had never received the letter.B. For years, she often talked about the letter.C. She didn't forgive her daughter at all in all her life.D. She read the letter again and again till she die.30.(单项选择题)(每题 2.00 分) It was not→ ←she took off her dark glasses→ ←I realized she was a famous actress.A. when; thatB. until; thatC. until; whenD. when; then31.(单项选择题)(每题 2.00 分) How could we possibly think that keeping animals in cages in unnatural environments-mostly for entertainment purposes is fair and respectful?Zoo officials say they are concerned about animals. However, most zoos remain "collections" of interesting "things" rather than protective habitats. Zoos teach people that it is acceptable to keep animals bored， lonely, and far from their natural homes.Zoos claim to educate people and save endangered species， but visitors leave zoos without having learned anything meaningful about the animals natural behavior, intelligence, or beauty. Zoos keep animals in small spaces or cages, and most signs only mention the species name, diet, and natural range. The animals normal behavior is seldom noticed because zoos don’t usually take care of the animals natural needs.The animals are kept together in small spaces, with no privacy and little opportunity for mental and physical exercise. This results in unusual and self-destructive behavior called zoochosis. A world-wide study of zoos found that zoochosis is common among animals kept in small spaces or cages. Another study showed that elephants spend 22 percent of their time making repeated head movements or biting cage bars, and bears spend 30 percent of their time walking back and forth, a sign of unhappiness and pain.Furthermore, most animals in zoos are not endangered. Captive breeding of endangered big cats, Asian elephants, and other species has not resulted in their being sent back to the wild. Zoos talk a lot about their captive breeding programs because they do not want people to worry about a species dying out. In fact, baby animals also attract a lot of paying customers. Havent we seen enough competitions to name baby animals?Actually, we will save endangered species only if we save their habitats and put an end to the reasons people kill them. Instead of supporting zoos, we should support groups that work to protect animals natural habitats.The author tries to persuade readers to accept his argument mainly by→←.A. pointing out the faults in what zoos doB. using evidence he has collected at zoosC. questioning the way animals are protectedD. discussing the advantages of natural habitats32.(单项选择题)(每题 2.00 分) When Thomas Butler stepped off a plane in April 2002 on his return to the United States from a trip to Tanzania, he set in motion a chain of events that now threatens to destroy his life. A microbiologist at Texas Tech University in Lubbock, Butler was bringing back samples of the plague bacterium Yersinia pestis for his research. Yet on re-entering the country, he is alleged to have passed right by US customs inspectors without notifying them that he was carrying this potentially deadly cargo. That move and its consequences have led the federal government to prosecute Butler for a range of offences. If convicted on all counts, he could be fined millions of dollars and spend the rest of his life in jail.The US scientific community has leapt to butlers defense, arguing that his prosecution is over- zealous, alarming and unnecessary. The presidents of the National Academy of Sciences。
基于鱼类和底栖动物生物完整性指数的济南市水体健康评价
Assessment of the Water Quality in Jinan City by Using both Fish and Benthic-MacroinvertebrateIndex of Biotic Integrity作者： 刘麟菲[1,2];徐宗学[1,2];殷旭旺[3];李福林[4];王汨[3]作者机构： [1]北京师范大学水科学研究院,北京100875;[2]城市水循环与海绵城市技术北京市重点实验室,北京100875;[3]大连海洋大学水产与生命学院,辽宁省水生生物学重点实验室,辽宁大连116023;[4]山东省水利科学研究院,山东济南250013出版物刊名： 环境科学研究页码： 1384-1394页年卷期： 2019年 第8期主题词： 生物完整性指数;箱体图法;累计系数法;济南市摘要：F-IBI (fish index of biological integrity,鱼类生物完整性指数)和B-IBI (benthic-macroinvertebrate index of biological integrity,底栖动物生物完整性指数)在大尺度流域范围内应用较广,但在城市水体中的应用研究较少.为了解F-IBI和B-IBI在城市水体中的适用性,分别于2014年和2015年的5月、8月和10月分6次对济南市水体进行野外采样调查,共设46个采样点(其中,12个采样点位于水库,34个采样点位于河流),采集底栖动物和鱼类,并测定了23个水环境因子.依据生物物种丰富度、种类个体数量比例、敏感性和耐受性、营养结构、繁殖共位群、物种多样性等功能属性,共计算底栖动物生物参数27个、鱼类生物参数22个.采用箱体图法和累计系数法,分别对河流型水体和水库型水体的生物参数进行筛选.根据百分位数法,共划分健康、较好、一般、较差、极差5个等级.通过Pearson相关性检验法判定鱼类和底栖动物评价结果的一致性.结果表明:①底栖动物总分类单元数、BMWP指数、鱼类物种数、鱼类个体数为河流型水体和水库型水体共同核心参数.②鱼类评价结果显示,健康样点6个、较好样点7个、一般样点9个、较差样点12个、极差样点12个,底栖动物依次分别为6、6、8、17、9个.③F-IBI和B-IBI相关系数为0.56,相关性较为显著.研究显示,济南市南部黄河区、小清河区东部生物完整性较高,城区东部及北部徒骇马颊河区生物完整性较差,鱼类和底栖动物评价结果具有较强的一致性.。
通用经典英语作文模板
The important model of English writingHowever important you consider…to be1,generally speaking …(according to the statistics shown by the pie chart2 )， there is no denying the fact that …has become a popular topic talked about not only by…but by…as well. Furthermore, people are increasingly coming to realize something important will have to be done to do… due to the fact that…Maybe you will ask why I do think it is important that…As a popular saying goes ,every coin has two sides.Some assert that …Others maintain that …Still others think a must is to do …Though there is no simple or uniform answer to the vexing question, here are some vital ways I must single out that maybe help you get a relatively clear picture of the include query5 . At the beginning …Secondly… Thirdly …Last but not least important resort is that…And you will also ask how to do …In my eyes, much more close attention can not too be paid not only to all the authorities to make some strong measures to put… under control but also to all the people to set up the sense of protecting…from…I think ,and you will accept that the more effort to pay , the brighter the future will be, although a long way is waitingfor us to go.一些重要句型：1.✓No matter important you regard something to be…{think of …as ……},when it comes to… ,but the fact remainsthat…✓Maybe you have taken for granted that something is important for a country ,a people ,a region, throughoutthe world to survive.✓Others opening sentences often usedWhy is it important for …to do…? Objectively speaking, different people have different opinions onthe same vexed question under different condition.Some people believe that…Others argue that …Still others assert that …Butthe real reason ,as I suggest is that……The governments can’t be too strongly expected to take great measures to put under control the pollutedenvironment affecting heavily the people’s life andhealth.2.According to the pie chart showing that the numberof …reaching in the neighbor of …in October is astwice as in the same period of last year, ascribed tothe growth of the globalization of economy ,societyand politics.3.✓Maybe you will ask “What is it on earth that makes it paramount for us to do …?”✓Here are some sentences about itIt’s of interest /important …for …to do …It is important(/necessary/urgent/desirable/advisable/expensive /comfortable /convenient/…for…to do.It is about /high time that…It is about to wake up to the fact that …It is high time to come to term with the fact that…It is public knowledge that …It is stands to reason that …It i high time to take stoke of the present situation.It is never too late to mend ./to do …in order for …to do …4.Here are some saying usually seenIn Rome ,do as the Romans do .The child is father of a man.The grass is always green on theothers sideof the fence Now time is ripe for …to …do …5.Here some sentences about there beThere is no simple answer to the question, but here are some thoughts I suggested that might help you deal with this vexed question.There is no quicker method of disposing of patient than by Singled out, Pointed out, Emphasized, seem … from among That clause believed, reported, said, accepted , estimated, known, discovered considered evidenced, supported, That clausegiving them what they are asking for.There is no better way to do …There is no social problem that is more incumbent upon us to understand than this of the role of custom.There is no point in trying to make the wings move like a bird’s, as other have already tried without success.There is no use crying over spilt milk.There is no getting away from …one has to admit the truth of …unpleasant.There is big money in doing …There is no denying the fact that …There is no telling that…There is no evidence that…There is no double that…There is no better way than to do …There is no time for present to do…6. While …the fact remains that…7. It is no longer impossible however ,that if…,the outlook for the future will become even brighter, with…doing …But it ought to be pointed out that Rome was not built in a day . So we shall have a long way to go.Here are some examples:OneAir pollution , one of the mos t severe environmental problems that have greatly impacted the human being, is becoming more and more serious. Today , no matter how faster you regard the social development to be than ever before ,impartially speaking ,here is no denying the fact ,as can be seen from these two pictures easily by studying them carefully that air pollution has been a hot topic talked about by most citizens living in some big cities in China ,such as Beijing ,Tianjin, Xi’an and the like. With the development of Chinese economy ,politics and society, there is no time for these cities to put under control the air pollution, a problem badly affecting the life and production of Chinese people greatly, especially in some cosmopolitan cities.Given the dreadful air pollution ,it may be asked what on earth it is that resulted in the conditions. There is no simple answer to this complex issue, but here are some thoughts or reasons I suggest that might help you get a relatively clear picture of the vexing problem. To begin with ,the rising number of car is an important cause contribution to the pollution due to some air pollutants’ being discharged into the air from them. Secondly ,not more a positive role in our economy construction than a negative effect on our condition have been played by some state-owned enterprise ,which were in the past ,are now ,andwill be in the future releasing some suspend harmful particles into the air.Certainly ,there are some other reasons working for the pollution.Maybe you will ask “what on earth is it that we should do ?”Personally it’s high time that some strong measures were taken by the governments to control the expansion of the number of cars and to move these polluting environment state-owned factories out of cities. On the other hand ,it cannot be too strongly emphasized that time is ripe to the air pollution. Everyone should raise the awareness of environmental protection and swing into action to prevent the air from pollution. Although the outlook of the environment for the future will be ever brighter, there is still a long way waiting for us to go.Note:✓Today the best estimate is that …No doubt ,this is only the beginning. In the future ,the conditions will be better.✓Bear in the mind that it is never too late to swing into action ,to beautify our living conditions.✓In my opinion, although what’s done cannot be undone ,and there is no use crying over the split milk and it’s never too late to mend. It is high time that…Furthermore ,it can not be strongly emphasizes that time is ripe for usto wake up the air pollution.Exercises:A: the greatly increasing pollution ←→the food production B: value of time or money.C: smokingTwoWhat is shown by these two pictures ?Great changes about world commercial fish fishing had taken place nearly a century from 1900 to 1995.The first picture depicts one happy and cheerful fishing boat wondering among schools of fish in 1900.On the contrary ,the second shows us that a lonely pitiful fish has few choices but to be caught by a counties number of fishing boats. These great changes are less the result of development of shipbuilding and fishing industry than that of destruction of the natural balance of the sea.What on earth is it that the drawer of these pictures tries to want to show? By studying them carefully ,a conclusion can be drawn easily that, with the development of the world commercial fishing ,the balance has been destroyed seriously. Therefore ,there is no time for human to keep the natural balance ,not to unbalance it ,which is what the author tries to imply.However ,how to protect the natural balance destruction and what measures to take on earth ? As far as I’m concerned ,although the solutions to them are complex, here are two ways that might throw some light onto these vexing issues and maybe help you get a relative clear picture of them .On the one hand, it cannot be too strongly emphasized that great measures should be made up by the governments to put under control the commercial fishing ;no matter how important it’s regarded to be. On the other hand ,it’s high time that much close attention should be paid by every person to it as an attempt to make the destroyed balance better than before. The more efforts and attention ,the brighter the outlook for natural balance is in the future I think .Yet ,a long way is still waiting for us to go.ThirdGreat changes in people’s diet have taken place in the past five years from1995 to2000.However important you regard the grain to be for our bodies. Objectively speaking ,there is no denying the fact ,which can be concluded from the table depicting the diet’s changes by studying it carefully ,that the people’s main attention has been aviated from the grain to the milk and meat. Thus ,the need for the grain decreases gradually, at the same time the consumption of the milk and meat is on the increase by and by .What on earth is it that makes people pay more attention to the milk andmeat than to the grain ? To be frank ,there is no simple answer to this question, and different people have different views due to different reason, but here are some thoughts I single out that might cast some light onto the vexed issue and help you get a relative clear picture of it .Firstly, it has been realized by most people that the important way to keep body in good shape is to have to keep a look-out for their diets everyday. Secondly,some foods such as milk ,meat ,and so on, being dear for people in the past ,now can be within the reach of the ordinary people due to the improved living standards .Certainly, there are still some other reasons ,apart from the above two ones ,contributing to the great changes too.As far as I am concerned ,a key point accounting for these changes consists in the ameliorated living standards. With much more close attention to the quality of living ,I think , there will be more and more people raising awareness of their diet ,d lifting their living standard.。
TPO 46 Reading 3 解析
Passage 1Q 1正确答案：B解析：原句意为，保护生物学家们一直担心生物物种灭绝会对整个生态系统的稳定性产生重要影响。
其中的significant意为“重要的，重大的”，四个选项中，A意为“直接的”，B意为“重要的”，C意为“长期的”，D意为“令人惊讶的”，只有B符合要求。
Q 2正确答案：C解析：第1段第2、3句指出，如果一个生态系统中失去了大量的物种，或者如果一个生态系统中失去了某一个重要的物种，这些都会对整个生态系统产生重要影响。
C是对这两句内容的综合概述，故为正确答案。
Q 3正确答案：B解析：第1段最后一句指出，由于没有海獭狩猎，海胆的数量激增，它们吃掉了绝大部分海藻。
B是对原文中in the absence of sea otter predation, sea urchin populations exploded and consumed most of the kelp and other macro-algae的同义转述。
Q 4正确答案：A解析：原句意为，如果生态系统的种群比较多的话，它的食物网会更复杂，在营养角色方面，种群会更冗余。
其中的redundancy意为“重复，冗余”，四个选项中，A意为“重复”，B意为“多样性”，C 意为“要求”，D意为“复杂性”，只有A符合要求。
Q 5正确答案：A解析：第2段主要阐述了一个理论：和物种贫瘠的生态系统相比，物种丰富的生态系统可能更稳定些，以及三个支持该理论的观点。
A符合要求。
Q 6正确答案：D解析：D是对第2段中给出的第一个原因with greater redundancy among species in terms of their nutritional roles的同义转述。
Q 7正确答案：C解析：高亮句的意思是，在一个物种丰富的生态系统里，疾病可能会传播得更慢些，因为绝大多数物种的数量不那么庞大，这使得同一个物种的个体能有更大的空间，这能阻碍疾病在个体间的传播。
托福阅读真题第223篇CrownofThornsStarfishandCoralReefs
托福阅读真题第223篇CrownofThornsStarfishandCoralReefs托福阅读真题第223篇Crown of Thorns Starfish and Coral ReefsCrown of Thorns Starfish and Coral ReefsParagraph 1：The crown of thorns starfish, Acanthaster Tlanci, is large, twenty-five to thirty-five centimeters in diameter, and has seven to twenty-one arms that are covered in spines. It feeds primarily on coral and is found from the Indian Ocean to the west coast of Central America, usually at quite low population densities. Since the mid-1950s, population outbreaks at densities four to six times greater than normal have occurred at the same time in places such as Hawaii, Tahiti, Panama, and the Great Barrier Reef. The result has often been the loss of a fifty percent to nearly one hundred percent of the coral cover over large areas.1. According to paragraph 1 all of the following statements about crown of thorns starfish are true EXCEPTO Crown of thorns starfish usually have several arms covered in spines.O Crown of thorns starfish's main food is coral.O Crown of thorns starfish normally live in high population densities.O Crown of thorns starfish have caused a significant reduction in coral cover over large areas.Paragraph 2：A single Acanthaster can consume five to six square meters of coral polyps per year, and dense populations can destroy up to six square kilometers per year and move on rapidly. Acanthasters show a preference for branching corals, especially Acroporids. After an outbreak in a particular area, it iscommon to find that Acroporids have been selectively removed, leaving a mosaic of living and dead corals. In places where Acroporids previously dominated the community devastation can be almost complete, and local areas of reefs have collapsed.2. What can be inferred from paragraph 2 about a coral reef that has a small number of Acroporids？O It will collapse completely after Acanthaster consumes the Acroporids.O It will lose the Acroporids before the other corals when Acanthaster attack it.O It will have a mixture of living and dead Acroporids after an Acanthaster attack.O It will have a dense population of Acanthaster for several years.Paragraph 3：Areas of dead coral are usually colonized rapidly by algae and often are later colonized by sponges and soft corals. Increases in abundance of plant-eating fish and decreases in abundance of coral-feeding fish accompany these changes. Coral larvae settle among the algae and eventually establish flourishing coral colonies. In ten to fifteen years the reefs often return to about the same percentage of coral cover as before. Development of a four-species diversity takes about twenty years.3. Which of the following is NOT mentioned in paragraph 3 as a consequence of the destruction of an area of a coral by Acanthaster？O Algae colonize the dead area.O Plant-eating fish increase in number.O Coral larvae disappear.O Species diversity recovers fully over time.Paragraph 4：two schools of thought exist concerning the cause of these outbreaks. One group holds that they are natural phenomena that have occurred many times in the past, citing old men’s recollections of earlier outbreaks and evidence from traditional cultures. The other group maintains that recent human activities ranging from physical coral destruction through pollution to predator removal have triggered these events.Paragraph 5：One theory, the adult aggregation hypothesis, maintains that most species is more abundant than we realize when a storm destroys coral and causes a food shortage. The adult Acanthasters converge on remaining portions of healthy coral and feed hungrily. Certainly there have been outbreaks of Acanthaster following large storms, but there is little evidence that the storms have caused the enough reef damage to create a food shortage for these starfish.4. According to paragraph 5, what is an important weakness of the adult aggregation hypothesis？O It is based on studies of the deeper parts of coral reefs.O It fails to explain the abundance of Acanthaster in the deeper parts of coral reefs.O It fails to explain why Acanthaster feed hungrily on healthy coral after a storm.O It is not supported by evidence that storms rusult in food shortages for Acanthaster.Paragraph 6：two other hypotheses attempt to explain the increased abundance of Acanthaster after episodes of high terrestrial runoff following storms. The first hypothesis is that low salinity and high temperatures favor the survival of the starfish larvae. The second hypothesis emphasizes the food web aspect, suggesting that strong fresh water runoff brings additionalnutrients to the coastal waters, stimulating phytoplankton production and promoting more rapid development and better survival of the starfish larvae.5. What can be inferred from paragraph 6 about the diet of Acanthaster larvae？O Phytoplankton is an important food source for them.O Storm water runoff washes away important nutrients they need.O When water temperature rises they have difficulty finding enough food.O Storms add needed salt to their diet.Paragraph 7：Those favoring anthropogenic (human influenced) causes have pointed to the large proportion of outbreaks that have been near centers of human populations. It has been suggested that coral polyps are the main predators of the starfish larvae. Destruction of coral by blasting and other bad land use practices would reduce predation on the starfish larvae and cause a feedback in which increases in Acanthaster populations cause still further coral destruction. Unfortunately, there are too few documented instances of physical destruction of coral being followed by outbreaks of Acanthaster for these hypotheses to be fully supported.6. Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information.O Blasting and other bad land use practices would cause the destruction of coral and increase the number of predators that feed on Acanthaster larvae.O Bad land use practices would reduce predation onAcanthaster larvae and increase the starfish population which would cause more coral destruction.O A reduction of bad land use practices would reduce coral destruction by increasing the survival of Acanthaster larvae and their predators.O The destruction of coral through land use activities would cause a decrease in the number of predators that feed on Acanthaster larvae.Paragraph 8：Another group of hypothesis focuses on removal of Acanthaster's predators. Some have suggested that the predators might have been killed off by pollution whereas others have suggested that the harvesting of vertebrate and invertebrate predators of Acanthaster could have reduced mortality and caused increased abundance of adults. The problem with this group of hypothesis is that it is difficult to understand how reduced predation would lead to sudden increases in Acanthaster numbers in several places at the same time in specific years. It seems probable that there is no single explanation but that there are elements of the truth in several of the hypotheses. That is there are natural processes that have led to outbreaks in the past, but human impact has increased the frequency and severity of the outbreaks.7. Why does the author state that “it is difficult to understand how reduced predation would lead to sudden increases in Acanthaster numbers in several places at the same time in specifi c years”?O To indicate the difficulty in proving that increases in Acanthaster numbers occur at the same time in different areas of the world.O To identify a problem with a hypothesis that associates theincrease in the population of Acanthaster with a removal of its predators.O To argue against the hypothesis that human activities cause sudden population outbreaks of Acanthaster in different places at the same time.O To argue against the view that the predators of Acanthaster decline because of pollution and harvesting by humans.8. What does the author conclude in paragraph 8 about the causes of sudden population increases of Acanthaster?O A sudden population increase in the Acanthaster population could be attributed to natural process as well as human activities.O There are no elements of truth in the hypothesis proposed to explain sudden population increases of Acanthaster.O It is possible to offer a single explanation for sudden population increases of Acanthaster.O Natural processes have been responsible for sudden population increases of Acanthaster in the past while present outbreaks are due to human activities.Paragraph 2：■A single Acanthaster can con sume five to six square meters of coral polyps per year, and dense populations can destroy up to six square kilometers per year and move on rapidly. ■Acanthasters show a preference for branching corals, especially Acroporids. ■After an outbreak in a partic ular area, it is common to find that Acroporids have been selectively removed, leaving a mosaic of living and dead corals. ■In places where Acroporids previously dominated the community devastation can be almost complete, and local areas of reefs have collapsed.9. Look at the four squares [■ ] that indicate where the following sentence can be added to the passage.The crown of thorns starfish is a coral reef predator that preys on coral polyps.Where would the sentence best fit?10. Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some answer choices do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points.Attempts have been made to explain the sudden increases in Acanthaster populations since the mid-1950s and their impact on coral reefs.Answer ChoicesO Larvae Acanthaster populations have preyed on coral reefs and caused the loss of coral cover over large areas and the collapse of some coral reef communities.O Acanthaster outbreaks have been attributed to natural phenomena such as stroms that have created favorable conditions for the rapid development of the starfish larvae.O Acanthaster outbreaks are the results of natural processes that have led to some increases in the past, as well as of human impact that has sped up the frequency and severity of the outbreaks.O There are several hypotheses trying to explain the Acanthaster outbreaks but none have elements of the truth because they contradict each other.O The crown of thorns starfish, Acanthaster Tlanci, is large,twenty-five to thirty-five centimeters in diameter, and has seven to twenty-one arms that are covered in spines.O The favorable anthropogenic causes, such as destruction of coral by blasting and other bad land use practices, have provided Acanthaster more food sources and therefore stimulate its population outbreaks.答案TF223-Crown of Thorns Starfish and Coral Reefs（答案文章最后）托福阅读真题第223篇Crown of Thorns Starfish and Coral Reefs。
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ENVIRONMENTAL ASSESSMENTDevelopment of a Fish-Based Index of Biotic Integrity for Wadeable Streams in Southern ChinaYintao Jia •Xiaoyun Sui •Yifeng ChenReceived:8July 2012/Accepted:12July 2013/Published online:28July 2013ÓSpringer Science+Business Media New York 2013Abstract With economic development in China,human-induced pressures on aquatic environments have grown and created an urgent need for tools measuring the ecological condition of aquatic systems.However,biological indica-tors for wadeable streams in China were poorly developed.This study developed and validated a multi-metric index of fish assemblages for wadeable streams of southern China to meet the requirement of the water project which has been carried on in China in recent years.Fifty-seven stream sites were sampled in April–May and November–December 2010to develop an index of biotic integrity.A set of 45candidate metrics were evaluated for range,responsiveness and redundancy,resulting in the selection of six metrics for the index:number of native species,number of rheophilic species,proportion of benthic riffle individuals,number of lithophilic species,number of omnivore species,and number of fish per hour sampling.The publicly available census data were used as independent data set to validate our method.Twenty-three sites were assessed as subject to significant (SP)or non-significant pressures (NSP)based on anthropogenic pressure evaluation.Our index per-formed well in discriminating NSP and SP sites,which suggested that our method could provide an accuratemeasure for wadeable streams ecosystem condition.We believe this integrated approach would meet the require-ments for the water projects of China,and the process of developing the method could be used as reference for managing the subtropical streams in other areas of China or other states.Keywords Index of biotic integrity ÁWadeable streams ÁFish ÁSouthern ChinaIntroductionWater is one of the most important natural resources forhuman beings (Vo¨ro ¨smarty and others 2010).However,aquatic ecosystems around the world were subjected to intense human activities (Vitousek and others 1997),such as water regulation (Nilsson and others 2005)and land cover change (Allan 2004).Consequently,many countries have progressively published legislations and regulations to manage these ecosystems.For example,the United States published the U.S.Water Pollution Control Act Amend-ment of 1972to protect the biological integrity of aquatic ecosystems (U.S.Congress 1972).European Union estab-lished The European Union’s Water Framework Directive to protect and manage the water resource of European (EC 2000).In order to guide management actions effectively,the processes of the human-induced pressures and their effects on waterbody should be understood in advance (Lopez and others 2009).Therefore,establishing monitor and manage tools have become a pared with physical and chemical monitoring,the biological one,could give an integrative and reliable measure for biotic condition of aquatic systems and be used in environmental assessment popularly (Angermeier and Karr 1986;Y.Jia ÁX.Sui ÁY.Chen (&)Laboratory of Biological Invasion and Adaptive Evolution,Institute of Hydrobiology,Chinese Academy of Sciences,7Donghu South Road,Wuhan 430072,Hubei,People’s Republic of China e-mail:chenyf@ Y.Jiae-mail:jiayintao@X.SuiSchool of Life Sciences,Peking University,Beijing 100871,People’s Republic of ChinaEnvironmental Management (2013)52:995–1008DOI 10.1007/s00267-013-0129-2Karr1987;Adams2002).Fish was one of the best bio-logical indicators for evaluating aquatic health(Karr and others1986).It was also proposed as a biological quality element of water bodies(EC2000).As a result,fish-based indices have become important assessment tools for water resource management over the world(Oberdorff and others 2002;Breine and others2004;Pont and others2006;Noble and others2007;Cheimonopoulou and others2011;Terra and Arau´job2011;Meixler2011).Among manyfish-based methods,the index of the biotic integrity(IBI)was the most commonly used one(Simon and Lyons1995).The IBI,based onfish assemblage characteristics,wasfirst described by Karr(1981)and later refined by Fausch and others(1984)and Karr and others (1986).The original version,consisting of12metrics related to species composition,trophic composition and health and abundance offish,wasfirst used in the Mid-western USA stream,and then to the whole world(Simon and Lyons1995).However,several studies found that IBI must be modified with different water body types and areas due to the substantial differences infish faunas(Fausch and others1984;Miller and others1988;Simon and Lyons 1995).Multiple versions of IBI were therefore developed (Oberdorff and Hughes1992;Minns and others1994; Bozzetti and Schulz2004;Ode and others2005;Hermoso and others2010;Hallett and others2012).China has abundant water resource,but also is confronted with the confliction between development and environ-mental conservation.Intensive human activities,such as deforestation,agriculture,urban,and industrial develop-ment,have caused the degradation of aquatic environment (Huang and others1995;Wang and Dou1998).How to manage water resource has become a severe issue for sus-tainable development of China(World Bank2001).In order to balance the confliction between environmental protection and economic development,many projects have been car-ried out by Chinese government in recent years.One of the most important projects for aquatic ecosystem was‘‘The Major Projects on Control and Rectification of Water Body Pollution(2005–2020)’’(TMPCRWBP).This project was designed to provide scientific support for controlling and managing water pollution in China.Thus,manyfish-based methods including IBI have been used to evaluate the aquatic condition of China(Zheng2006;Zhu and Chang 2008).Despite many studies applying IBI in China,there were still some problems in the application.For example, metrics were screened based on the‘‘range’’criteria or(and)‘‘professional judgment’’without any statistical analysis, and no validated methods were used to evaluate the effi-ciency of the IBI.Furthermore,all the studies focused on large rivers,whereas wadeable streams,the most threatened ecosystems,were ignored(Magalha˜es and others2008). Most of the wadeable streams belonged to headwater(order 1–3)(Vannote and others1980).As the beginnings of river networks,headwater streams were critical aquatic–terres-trial interface for inorganic and organic materials entering river networks(Vannote and others1980).Knowing the characteristics of headwaters would help manager to understand the natural properties of larger downstream riv-ers(Lyons2006).However,wadeable streams have received less protection and have been heavily modified by human activities for rarely supporting importantfisheries(Dodds and others2004;Lyons2006).If the status continue,the deteriorative wadeable streams would ultimately influence the functions of the entire river ecosystems(Vannote and others1980;Lyons2006).Our objective was to develop an IBI suitable for sub-tropical wadeable streams in southern China.The method of the study could be later used for water project in other areas.In addition,it could provide potential implications for the management of subtropical streams in other states. Materials and MethodsStudy AreaThe Dongjiang River is one of the three major tributaries of the Pearl River,the largest river system in southern China. With a watershed area of35,340km2and a total length of 562km,it originates from Jiangxi province and locates mainly in Guangdong province.The area experiences a humid subtropical climate and the mean annual tempera-ture is about21°C(Liu and others2010).The Dongjiang River is a warm water river with mean annual water tem-perature about22°C(Pan1991).As the main water sources for the Guangdong province and Hong Kong,the Dongjiang River has been unfortunately deteriorated owing to the demographic and economic growth,intensive agriculture and industrial production,and increased urbanization(Jia and Chen2013).Therefore,one of the TMPCRWBP projects was carried out from2009.Fish SamplingWe studied57wadeable sites in four tributaries of the Dongjiang River.The Xunwu River and the Dingnan River were the major tributaries of the upstream.The Xinfengjiang River and the Zengjiang River were the major tributaries of midstream and downstream,respectively(Fig.1).River orders were assigned following Strahler(1957).All the sampling sites were the second and third-order streams. First-order streams were not included in the design because many of these sites were highly ephemeral in nature and hard to access.All the sites were surveyed during April–May and November–December2010.Fish assemblages weresampled using an electro-fishing gear consisting of two copper electrodes on bamboo handles,powered by a 24-V battery.The gear was operated by one person and two per-sons captured stunned fishes using dip nets.The sampling was carried out following the zigzag route across the sites.Sampling reaches were randomly selected along the rivers and had a length equal to 40times the mean wetted width (Lyons 1992;McCormick and others 2001).The minimal and maximal distance was 150and 550m,respectively.All fish captured were identified to species,counted and then released back into the stream.Candidate MetricsSix functional attributes were considered to define the list of candidate metrics:diversity,habitat,tolerance,trophic,migration,and abundance and condition (Table 1).Attri-butes assignment of the 78fish species,known from the study area,was based on the published literatures (Pearl River Fisheries Research Institute 1986;Pan 1991)(‘‘Appendix ’’section).Overall,45candidate metrics applied commonly in other studies were selected to develop the IBI in our study (Karr and others 1986;Simon and Lyons 1995;Lyons and others 2001;Harris and Sil-veira 1999;Breine and others 2004;Magalha˜es and others 2008).Metric ScreeningTo reduce the influence of the peak value and make the data approach normality,proportional variables were arc-sine-square root-transformed whereas other variables were020 kmXW020 kmXFJ020 km70 km0XWDNDNXFJZJZJFig.1Locations of sampling sites in the wadeable streams of the Dongjiang River.DN the Dingnan River,XW the Xunwu River,XFJ the Xinfengjiang River,ZJ the Zengjiang RiverTable1List of candidate metrics,expected response(ER) to human disturbance and screening result(SS)where they were rejectedRANG range,RESP responsiveness,REDU redundancy,Ffinal inclusion Candidate metrics Code ER SSSpecies diversityNumber of species NS;REDU Number of native families NNF;RESP Number of native species NNS;F Proportion of native individuals PN;RESP Number of introduced species NIS:RANG Proportion of introduced individuals PI:RANG Number of nativefish species,family Cyprinidae(excluding tolerant taxa)NNCyet;REDU Number of native Cyprinidae species NNCy;RESP Shannon–Wiener Diversity Index SWDI;REDU HabitatNumber of rheophilic species NRS;F Proportion of rheophilic individuals PNRS;REDU Number of benthic riffle species NBRS;RANG Proportion of benthic riffle individuals PNBRS;F Number of benthic native species NBNS;REDU Proportion of benthic native species individuals PNBNS;REDU Number of benthic species(excluding tolerant taxa)NBSet;REDU Proportion of benthic native individuals(excluding tolerant taxa)PNBSet;REDU Number of benthic intolerant native species NBINS;RANG Proportion of benthic intolerant native individuals PNBINS;REDU Number of water column species NWCS;RESP Proportion of water column species individuals PNWCS;RESP Number of water column native species NWCNS;RESP Proportion of water column native individuals PNWCNS;RESP Number of hider species NHS;RANG Proportion of hider water column individuals PNHS;RANG Number of hider native species NHNS;RANG Proportion of hider water column native individuals PNHNS;RANG Number of lithophilic species NLS;F Proportion of lithophilic species individuals PNLS;REDU ToleranceNumber of intolerant species NINS;RANG Proportion of intolerant individuals PNINS;RESP Number of tolerant species NTS:REDU Proportion of tolerant individuals PNTS:REDU Trophic functionNumber of herbivore species NHES;RANG Proportion of herbivore individuals PNHES;RANG Number of omnivore species NOS:F Proportion of omnivores individuals PNOS:RESP Number of carnivores species NCS:RESP Proportion of carnivores individuals PNCS:RESP MigrationNumber of migrating species NMS;RANG Proportion of migrating individuals PNMS;RANG Abundance and conditionNumber offish per hour sampling CPUE;F Number of native individuals per hour sampling CNPUE;REDU Number of introduced individuals per hour sampling CIPUE:RANG Number of anomalies or disease individuals per hour sampling CAPUE:RANGlog-transformed,prior to analysis.Candidate metrics were screened for range,responsiveness,and redundancy.First, metrics were rejected if their ranges were\3or[70%of values were zero because the discrepancies among streams were usually obscured for small ranges(Magalha˜es and others2008;Kanno and others2010).Second,a Mann–Whitney U test was used to examine the responsiveness of the remaining candidate metrics discriminating the mini-mally and the most disturbed sites(Mebane and others 2003).The main human activities in our study areas included mining,land-use,artificial drainage systems construction,and so on.Mining could be related to point source discharges.The major land-use types in the basin were agriculture(occupied14.09%)and urban(occupied 9.39%)at2009(Ren and others2011),which could result in non-point source pollution.The construction of artificial drainage systems could be related to connectivity of the river.Due to suffering from the similar human disturbance, the minimally and the most disturbed sites were selected by referring to the criteria of Lyons and others(2001).A site judged to be minimally disturbed was not impounded,had no artificial drainage systems construction and received minimal point and non-point source pollution.Conversely, the sites with lots of dams and received maximal point and non-point source pollution were selected to be the most disturbed.Third,redundancy was measured following two steps:(1)a principal component analysis(PCA)was used to detect the metrics with a low variance(Hering and others 2006).Metrics with a factor loading\0.7were failed to past the test(Breine and others2004).(2)Pearson’s cor-relation coefficient was used to test redundancy.Pairs of the metrics with strong correlations(r[0.75)were con-sidered redundant(Magalha˜es and others2008).The redundant metrics were then selected basing on their responsiveness and the applicability to the study area (Breine and others2004).Reference ConditionReference condition was the standard or benchmark for current condition to compare with(Stoddard and others 2006).It could be established basing on historical data, paleoecological data,reference sites,and observed value (Hughes1995).Regrettably,historical and paleoecological data for the Dongjiang River were very insufficient.In addition,it was unrealistic tofind some sites with a pristine state due to the agriculture and urbanization development in study area.Therefore,the most possible method to estimate reference condition was based on the observed value.Our survey included large geographical scale and variety of habitat types,so we assumed that the data of degraded and acceptable benchmark conditions were obtained in the survey.As a result,the upper threshold for metric was set on the best condition observed.For exam-ple,the highest numbers of native species were nine for second-order and11for third-order stream.The highest values of each order were used as reference condition of that metric.Metric ScoringEach selected metric was scored with reference value on a continuous scale from0for highly degraded habitat to10for the reference condition(Minns and others1994)(Table2). Upper threshold was the highest value observed and lower threshold was zero for most positive metrics(i.e.,values were higher in the reference condition)in this survey.For the omnivore metric(higher score was considered undesirable), the upper threshold was the lowest value observed(zero for our study)and lower threshold was the highest value.The upper thresholds of each metrics varied with stream sizes (Table2).Each metric score was calculated by a ratio of the observed value at the sampling site(O)and the referred value (R),that is,Individual IBI score¼O=RÂ10for positive metrics,and Individual IBI score¼10ÀO=RÂ10h ifor the omnivore metric.For example,the maximum number of rheophilic species among second-order stream sites was five,so a sampling site with three species was scored as six, i.e.,[(3/5)910].The maximum number of omnivore species was six for second-order streams,so a site with three species was scored asfive,i.e.,[10–(3/6)910].Scores for each metric were summed to give IBI scores which were divided intofive equal-width ranges(Minns and others1994): 0=Nofish,0\very poor B12,12\poor B24, 24\fair B36,36\good B48,48\excellent B60.Table2IBI metrics composition and scoring criteria used in order2 and3streamsMetric Scoring criteriaStream order2Stream order3Species diversityNumber of native species0–90–11 HabitatNumber of rheophilic species0–50–6 Proportion of benthic riffleindividuals0–51.35%0–67.76% Number of lithophilic species0–40–5 Trophic functionNumber of omnivore species6–09–0 Abundance and ConditionNumber offish per hour sampling0–3980–896Seasonal Variation of the IBIFish assemblages may vary with the change of the seasons and further influence the assessment results of the IBI(Karr and others1986).Sixteen sites sampled at both survey were used to test the seasonal variation of our IBI with a paired t test.If IBI scores were seasonally stable,the scores of16 sites between two seasons would be expected to have no significant difference.Performance of MetricsThe performance of metrics was evaluated with two tech-niques:(1)the relationship between metric and the IBI score was tested using Kendall’s tau(Angermeier and Karr 1986).This step was used to check the predicted responses of individual metrics as listed in Table1.(2)Individual metrics contributed to the overall IBI scores were analyzed through comparing IBI scores with artificial IBI scores (IBI-O)which were derived by omitting individual metric scores from the overall IBI.The relationship between the score of IBI and IBI-O was also assessed by Kendall’s tau (Angermeier and Karr1986).Index Validation Using an Independent Data Set Human activities would degrade river ecosystem either directly or indirectly through altering water quality,flow regime,biotic factors,etc.(Karr and Chu1999).Due to the tight relationship with river ecosystem,many human dis-turbance variables were used to assess the river status(Wang and others2008,Lopez and others2009).In order to test the efficiency of our IBI,we used the human disturbance data as an independent dataset to evaluate the site quality.Based on the availability of the data and the known effects on river health,four variables were selected:(1)percent of agricul-tural land(AGR),(2)percent of forested land(FOR),(3) percent of urban population(URB),(4)population density (POP)(Roth and others1996;Gary2007;Wang and others 2008).For metric1,3,and4the influence on river health was negative whereas metric2was positive.The data of human disturbance were obtained from publicly available census data published at2009by the municipal statistics bureau. These variables were quantified at subcatchment scale which was divided based on the administrative unit of the Dongjiang River basin for each site.The variable of AGR was calculated as percentage of agricultural land use in the subcatchment.The FOR was calculated as the percentage of the forest land-use in the subcatchment.The URB was estimated as the proportion of the urban population to total population.The POP was expressed as the number of pop-ulation at per square kilometer of the subcatchment.PCA analysis was used to give an integrated evaluation of these pressures(Magalha˜es and others2008;Lopez and others 2009),and then the evaluation was used to assess the sam-pling sites as subject to:significant(SP)and not-significant pressures(NSP).The IBI scores at NSP and SP sites were compared using Mann–Whitney tests(Magalha˜es and others 2008).If our IBI was suitable for study area,it should dis-criminate NSP and SP sites effectively.ResultsMetric ScreeningOf the45metrics tested,15metrics werefirst removed because their ranges were\3or[70%of values were zero (Table1).From the remaining30metrics,11failed the responsiveness test due to P value[0.05as shown in Tables1and3.The PCA analysis was carried out for the Table3Responsiveness anal-ysis of the candidate metricsAn*indicated that the metricfailed to past the analysis.SeeTable1for metric abbreviationMetrics P valueNS\0.01NNF*0.07NNS\0.01PN*0.37NNCyet\0.05NNCy*0.12SWDI\0.05NRS\0.01PNRS\0.01PNBRS\0.01NBNS\0.01PNBNS\0.01NBSet\0.01PNBSet\0.01PNBINS\0.01NWCS*0.06PNWCS*0.10NWCNS*0.06PNWCNS*0.10NLS\0.01PNLS\0.01PNINS*0.23NTS\0.05PNTS\0.05NOS\0.01PNOS*0.09NCS*0.58PNCS*0.09CPUE\0.01CNPUE\0.01remaining responsive metrics.Thefirst two PCA axes were selected to analysis the redundancy of metrics,because they accounted for69.68%of the total variation(51.33 and18.35%,respectively)and most metrics had the highest values on them.Five metrics were excluded because of the low factor loading on both axes(Table4). Pearson’s correlation analysis further suggested that some metrics,significantly contributed to the variance,were redundant.Eight metrics were excluded from the remaining metrics based on expert judgment and for relatively less responsiveness(Table1).Six metrics werefinally included in the IBI.They belonged to four functional attributes: diversity,habitat,trophic,and abundance and condition.Metrics DescriptionsThefinal suite of metrics was described below.Number of native species(NNS)this metric was limited to the native species in order to exclude the confounding effects from the alien species.Three alien species were common in the wadeable streams of the Dongjiang River.This metric therefore reduced the error from the presence of the alien species.Number of rheophilic species(NRS)rheophilic species fed and bred in riffles and rapids.This metric was used tomeasure the effects of the river impoundment and channelization(Toham and Teugels1999;Noble and others2007),which were likely the most common human disturbance in the Dongjiang River. Proportion of benthic riffle individuals(PNBRS)benthic riffle species lived on or near the bottom and usually did not feed on the surface(Noble and others2007),and were sensitive to the stream siltation and oxygen deficiency(Oberdorff and Hughes1992).The metric measured the habitat quality for bottom dwelling species.Number of lithophilic species(NLS)this metric was used as an indicator for habitat alterations resulted from siltation and substrate modification(Simon and Emery 1995).Silt was the common stream pollutant in the Dongjiang River,and this metric may be useful in distinguishing degraded streams for substantial silt loads. Number of omnivore species(NOS)this metric reflected the trophic aspect of environmental condition,and assessed the food web disruption by stressors in streams. Number offish per hour sampling(CPUE)this metric was used to reflectfish relative abundance(Karr and others1986).Biotic Integrity of the StreamsThe IBI scores ranging from11.3to47.8,with a median of 26.0showed that most sites(78.05%)were below good condition,and overall43.90%had a poor or very poor condition.The average IBI scores for the wadeable stream at four tributaries were36.4±8.9for the Xunwu River, 18.4±8.2for the Dingnan River,25.4±10.3for the Xinfengjiang River,and23.1±8.5for the Zengjiang River.The average IBI score at the Xunwu River was significantly higher than others(P\0.05,Mann–Whitney tests).Seasonal Variation of the IBIThe influence of seasonal variation was not significant for the IBI scores in our study(t=0.85,P=0.42).It was suggested that the seasonal change offish assemblage in the Dongjiang River did not affect thefinal results. Performance of MetricsCoefficients of concordance between IBI score and metric value indicated that all metrics but NOS were significantly positively correlated to the IBI score(Table5).All metrics showed the same response as the predicted.The IBI-O for each metric had high correlation with the IBI for both all regions and individual streams(Table5).Table4Factor loading offirst two components from PCA of can-didate metricsCandidate metrics Component12NS0.92-0.24 NNS0.91-0.22 NNCyet*0.66-0.56 NRS0.86-0.21 PNRS*0.36-0.55 PNBRS0.820.38 NBNS0.870.17 PNBNS0.170.93 NBSet0.800.28 PNBSet0.220.91 PNBINS0.760.38 NLS0.890.001 PNLS*0.680.27 SWDI*0.630.17 PNINS0.760.38 NTS*0.17-0.35 NOS0.84-0.36 CPUE0.751-0.26 CNPUE0.748-0.26An*indicated that the metric failed to past the analysis.See Table1 for metric abbreviationThe highest Kendall’s tau value for the all regions was 0.954for PNBRS.For the individual streams,the highest Kendall’s tau values were 1.000(PNBRS,P \0.01)for the Dingnan River and Zengjiang River,0.970(NLS,P \0.01)for the Xunwu River and 0.956(NLS,P \0.01)for the Xingfengjiang River (Table 5).IBI ValidationTwenty-three sites for which we obtained the complete human-induced pressure data were used to test the effi-ciency of the IBI.The first component of the PCA explained 69.46%of the total variance and the second component explained 19.79%.POP,URB,and AGR had positive loadings on the first axe,whereas FOR on the second axe (Fig.2).Therefore,sites with negative factor 1and positive 2scores were assessed as subject to not-sig-nificant pressures.Sites with other factor 1and 2scores were assessed as suffering from significant pressures.The results showed that six sites out of 23were subject to NSP,and others were SP (Fig.2).Compared with SP sites (Mean =23.2,SD =10.3),the average IBI scores of NSP sites (Mean =38.6,SD =11.7)were significant higher (P =0.01)(Fig.3).It was suggested that the IBI could discriminate NSP and SP sites effectively.DiscussionConsiderations in Our SamplingA crucial procedure for developing IBI was to obtain representative samples by using effective methods (Karr and others 1986).Many studies found that two factors could affect the sampling results:the efficiency and effortTable 5Kendall’s Tau coefficient between metrics value and IBI score and between IBI score and IBI-O MetricTotal IBI scores IBI-O scores DN XW XFJ ZJ TOT NNS 0.394**0.667*0.909**0.867**0.778**0.864**NRS 0.696**0.889**0.939**0.911**0.889**0.909**PNBRS 0.739** 1.000**0.848**0.911** 1.000**0.954**NLS 0.782**0.889**0.970**0.956**0.944**0.915**NOS -0.345*0.667*0.939**0.822**0.944*0.854**CPUE0.413**0.889**0.848**0.867**0.944**0.899**See Table 1for metric abbreviationDN the Dingnan River,XW the Xunwu River,XFJ the Xinfengjiang River,ZJ the Zengjiang River,TOT total sampling sites *P \0.05**P \0.01POPURBAGRFORFig.2River health assessment using census data for wadeable streams in the Dongjiang River.(Upper )PCA ordination plot for the four census data variables.(Lower )Site score plots;bigger black dots are NSP sites and smaller are SP sites.AGR percent of agricultural land,FOR percent of forested land,URB percent of urban population,POP population density。