TPO51托福阅读passage3:The Role of the Ocean in Controlling Climate原文文本+真题答案

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托福阅读真题第51篇E1NinoandtheSouthernOscillation

托福阅读真题第51篇E1NinoandtheSouthernOscillation

托福阅读真题第51篇E1NinoandtheSouthernOscillationBetween the ocean surface and the atmosphere. there is an exchange of heat and moisture that depends, in pat, on temperature differences between water and air. Even a relatively small change in surface ocean temperatures could modify atmospheric circulations and have far-reaching effects on global weather patterns.Along the west coast of South America, where the cool Peru Current sweeps northward,southerly winds promote upwelling (rising to the surface and flowing outward ) of cold.nutrient- rich water that gives rise to large fish populations. especially anchovies. The abundance of fish supports a large population of seabirds whose droppings (ale guano) produce huge phosphate rich- deposits that support the fertilizer industry. Near the end of the calendar year, a warm current of nutrient-poor tropical water often moves southward, replacing the cold, nutrient-rich surface water.In most years, the warming lasts for only a few weeks to a month or more, after which weather patterns usually return to normal and fishing improves. However, when conditions last for many months, and a more extensive ocean warming occurs, the economic results can be catastrophic. This extremely warm episode, which occurs at irregular intervals of two to seven years and covers a large area of the tropical Pacific Ocean, is now referred to as a major El Nino event, or simply El Nino.During a major El Nino event, large numbers of fish and marine plants may die. Dead fish and birds may litter the water and beaches of Peru; their decomposing bodies reduce the water's oxygen supply,which leads to the bacterial production ofhuge amounts of hydrogen sulfide. The El Nino of 1972-1973 reduced the annual Peruvian anchovy catch from 10.3 million metric tons in 1971 to 4.6 million metric tons in 1972. Since much of the harvest of this fish is converted into fish meal and exported for use in feeding livestock and poultry, the world's meal production in 1972 was greatly reduced. Countries such as the United States that rely on meal for animal feed had to use soybeans as an alternative This raised poultry prices in the United States by more than 40 percent.Why does the ocean become so warm over the eastern tropical Pacific? Normally in the tropical Pacific Ocean, there are the trades-persistent winds that blow westward from a region of higher pres sure over the eastern Pacific toward a region of lower pressure centered near Indonesia. The trades create upwelling that brings cold water to the surface.As this water moves westward, it is heated by sunlight and the atmosphere.Consequently, in the Pacific Ocean,surface water along the equator usually is cool in the east and warm in the west. In addition, the dragging of surface water by the trades raises the sea level in the western Pacific and lowers it in the eastern Pacific, which produces a thick layer of warm water over the tropical western Pacific Ocean and a weak ocean current (called the counter current) that flows slowly eastward toward South America.Every few years, the surface atmospheric pressure patterns break down, as air pressure rises over the region of the western Pacific and falls over the eastern Pacific. This change in pressure weakens the trades, and, during strong pressure reversals, east winds are replaced by west winds. The west winds strengthen the counter current, causing warm water to head eastward towardSouth America over broad areas of the tropical Pacific. Toward the end of the warming period, which may last between one and two years, atmospheric pressure over the eastern Pacific reverses and begins to rise, whereas, over the western Pacific, it falls. This seesaw pattern of reversing surface air pressure at opposite ends of the Pacific Ocean is called the Southern Oscillation. Because the pressure reversals and ocean warming are more or less simultaneous, scientists call this phenomenon the El Nino/Southern Oscillation, or ENSO for short. Although most ENSO episodes follow similar evolution, each event has its own personality, differing in both strength and behavior.1.Between the ocean surface and the atmosphere. there is an exchange of heat and moisture that depends, in pat, on temperature differences between water and air. Even a relatively small change in surface ocean temperatures could modify atmospheric circulations and have far-reaching effects on global weather patterns.。

托福TPO真题阅读答案解析

托福TPO真题阅读答案解析

托福TPO真题阅读答案解析托福TPO真题阅读答案解析只有愚者才等待机会,而智者则造就机会。

下面是店铺为大家搜索整理的托福TPO真题阅读答案解析,希望大家能有所收获,l 答案及题目解析Key:1.B2.A3.C4.C5.A6.B7.D8.D9.B10.C 11.D 12.B 13-14.125题目解析:1. In paragraph 1, what does the author say about the presence of a blowhole in cetaceans?(Factual Information Question)A.It clearly indicates that cetaceans are mammals.B.It cannot conceal the fact that cetaceans are mammals.C.It is the main difference between cetaceans and land-dwelling mammals.D.It cannot yield clues about the origins of cetaceans.相关原句:Their streamlined bodies, the absence of hind legs, and the presence ofa fluke and blowhole cannot disguise their affinities with land dwelling mammals.(Paragraph 1)本题解析:cannot disguise…意为“不能掩盖…”,因此“the presence of blowhole cannot disguise their affinities with land dwelling mammals”意思是“具有blowhol(出气孔)并不能掩盖这一事实:鲸类动物和陆栖哺乳动物有姻亲关系(affinities)”;B选项中cannot concea(不能隐藏)l恰好与 cannot disguise相吻合,并指出鲸类动物是哺乳动物的事实,因此选择B。

托福听力tpo51 全套对话讲座原文+题目+答案+译文

托福听力tpo51 全套对话讲座原文+题目+答案+译文

托福听力tpo51 全套对话讲座原文+题目+答案+译文Section 1 (2)Conversation1 (2)原文 (2)题目 (4)答案 (5)译文 (5)Lecture1 (7)原文 (7)题目 (9)答案 (11)译文 (11)Lecture2 (13)原文 (13)题目 (16)答案 (18)译文 (18)Section 2 (20)Conversation2 (20)原文 (20)题目 (22)答案 (24)译文 (24)Lecture3 (26)原文 (26)题目 (28)答案 (30)译文 (30)Lecture4 (32)原文 (32)题目 (34)答案 (36)译文 (36)Section 1Conversation1原文NARRATOR: Listen to part of a conversation between a student and her biology professor.MALE PROFESSOR: So the assignment is to reproduce one of the animal camouflage experiments we read about in our text book. Which experiment did you pick? FEMALE STUDENT: Well... I was wondering if I could try to reproduce an experiment that's kinda the opposite of what was discussed in the textbook?MALE PROFESSOR: So, instead of how and why an animal might hide itself, you want to do something about why an animal might want to be seen? Hmmm. Tell me more. FEMALE STUDENT: Well, I got the idea from one of the journals you said we should look at…it's an experiment about, um, they called them eyespots in the article? MALE PROFESSOR: Eyespots, sure, the patterns on the wings of moths and butterflies that are generally believed to scare off predators because they look like big eyes. FEMALE STUDENT: Yeah, except the article was about an experiment that disputes that theory.MALE PROFESSOR: Well, we know that the markings do scare the birds, but the idea that the spots look like eyes is, well that's just a commonly held belief.FEMALE STUDENT: So—that's not even based on research?MALE PROFESSOR: Well, this whole idea of moth or butterfly markings being scary because they look like eyes rests on how we imagine that their predators—like birds —perceive the markings. And we can never really know that. All we can do is observe bird behavior. But tell me more about the experiment.FEMALE STUDENT: OK, so the experiment looked at the shapes of the markings onmoth wings. The researchers wanted to know if the markings that were round or eye-shaped were more effective at deterring predators than square or rectangular markings.MALE PROFESSOR: OK…FEMALE STUDENT: Yeah. So, they attached food to paper models of moths, with different shaped marks drawn on the wings, to see how birds reacted. And what's interesting is, they realized that the round marks were not more effective at scaring birds than other shapes.MALE PROFESSOR: Were they less effective?FEMALE STUDENT: No, they were about the same... but what researchers did determine is that larger markings are more effective than smaller markings at scaring off prey. They called this phenomenon “visual loudness.”MALE PROFESSOR: Visual loudness, huh. Well, I guess it's not all that shocking, if you think about it.FEMALE STUDENT: So, anyway, is it OK? Can I repeat this experiment and write about it?MALE PROFESSOR: Yes, I think that'll work. The problem I foresee is, well, where? This is an urban campus...You'll have a hard time finding a good place to set up the experiment.FEMALE STUDENT: Oh, I-I wasn't planning on doing it on campus. I'm going home for spring break, and my family lives in the country, far from the nearest city. I can set it up in the backyard.MALE PROFESSOR: Good idea. Except one week is not a lot of time. So you'll need to make some adjustments to have enough data. I'd set up the experiment near a bird feeder, and get in as much observation time as you can.题目1.Why does the student talk with the professor?A. She wants permission to revise an experiment that she conducted earlier.B. She has a question about the findings of an experiment in the textbook.C. She wants to reproduce an experiment that is not in the textbook.D. She would like some advice about how to study butterfly and moth behavior.2.What does the professor say is a common assumption about certain markings on butterfly and moth wings?A. That the markings are usually hidden from viewB. That the markings attract some kinds of birds more than othersC. That some birds perceive the markings as large eyesD. That butterflies and moths use the markings to attract mates3.What were the results of the experiment that the student describes? [Click on 2 answers.]A. Birds reacted to round markings the same way they reacted to square markings.B. Large markings scared birds more than small markings did.C. Most birds ignored markings that looked like eyes.D. Birds were attracted to more colorful markings.4.Why does the professor mention a bird feeder?A. To suggest a strategy that may help the student carry out her task successfullyB. To recommend a place on campus that is suitable for the student's projectC. To discuss another experiment that has yielded surprising resultsD. To point out a problem in the design of the original experiment5.What can be inferred about the student when she says this:Professor: Well, we know that the markings do scare the birds but the idea that the spots looked like eyes is……well, that is just a commonly held belief.Student: So, that’s not even based on research?A. She is skeptical about what the professor just told her.B. She just realized that she designed her experiment incorrectly.C. She is worried that she misunderstood something that she read.D. She had assumed that there was scientific evidence for the theory.答案C C AB A D译文旁白:请听一段学生和其生物学教授之间的对话。

TPO51托福阅读passage3:The Role of the Ocean in Controlling Climate原文文本+真题答案

TPO51托福阅读passage3:The Role of the Ocean in Controlling Climate原文文本+真题答案

TPO51托福阅读passage3:The Role of the Oceanin Controlling Climate原文文本+真题答案第三篇:社会学The Role of the Ocean in Controlling ClimateTo predict what the climate will be like in the future, scientists must rely on sophisticated computer models. These models use mathematical equations to represent physical processes and interactions in the atmosphere, ocean, and on land. A starting point is usually based on current measurements or estimates of past conditions. Then, using a spherical grid laid out over the entire globe,thousands of calculations are performed at grid intersections to represent and assess how conditions in the air, in the sea, and on land will change over time. Because of their complexity and size, supercomputers are used to run full-scale climate models. Much of the uncertainty in their outputs comes from the way that various aspects of the climate are represented by different models, and even more so, because there are aspects of climate that are not well understood—one of which is how the ocean impacts climate.The ocean’s role in global warming stems principally from its huge capacity to absorb carbon dioxide and to store and transport heat. In the sea, photosynthesis by marine plants and algae, especially phytoplankton, removes great quantities of carbon dioxide from the atmosphere. Hence, the greater the growth (productivity) of phytoplankton in the sea, the greater the removal of carbon dioxide. But what controls the ocean’s productivity? There are several limiting factors, but results from a recent experiment suggest that in areas of the ocean where other nutrients are plentiful, iron may be one ofthe most important and, until recently, unrecognized variables controlling phytoplankton production. Some have proposed a radical, highly controversial and uncertain means to counteract global warming —adding iron to the oceans to induce phytoplankton blooms. Perhaps increased phytoplankton growth would use up a significant amount of carbon dioxide in the atmosphere, but perhaps not, and there might well be side effects that could be detrimental to the ocean ecosystem.Within the ocean, the production of limestone, in the form of calcium carbonate skeletons or shells, also reduces atmospheric carbon dioxide. However, when deposits of limestone become exposed and weathered on land or are recycled in the sea, carbon dioxide is released back into the atmosphere. What is not well understood is how much carbon dioxide resides in the sea and at what rate it is taken up and recycled. Relatively new research has also discovered beneath the sea a new and potentially significant threat to skyrocketing Earth temperature: gas hydrates. Gas hydrates are a solid, crystalline form of water, like ice, except that they contain additional gas, typically methane, and are often found stored in ocean sediments. Increased ocean temperatures could cause gas hydrates to dissociate, releasing massive amounts of methane gas into the atmosphere and cause undersea landslides in the process. Consequently, hydrates may, if released, significantly increase global warming as well as create a geologic hazard to offshore drilling operations.The ocean is also a great reservoir and transporter of heat. Heat from the ocean warms the atmosphere and fuels tropical storms. Heat is transported by currents from the equator to the poles. Ocean circulation is strongly controlled by wind and by the sea’s balance of salt and heat. Scientists think that climate warming may slow down circulation, while cooling may speed it up, but these responses are not well understood. Evaporation from the ocean also supplies the precipitation that creates fields of snow and ice at high latitudes. Snow and ice coverage change thereflectivity Earth’s surface and are an important influence on how much incoming radiation is either absorbed or reflected. Furthermore, clouds and water vapor in the atmosphere come mainly from the sea and strongly influence climate. Surprisingly, clouds are one of the least understood and most poorly modeled parts of the climate change equation. Most climate modeling grids fail to take into account common-sized cloud formations. Aerosols, tiny particles of soot, dust, and other materials, are thought to seed cloud formation scatter incoming radiation and promote cooling, but this effect, which would counteract warming, is also only superficially understood. Computer models of climate change must take into account all of the processes within the ocean, over land, and in the sky that potentially influence warming. No wonder there is such uncertainty.题目Paragraph 1To predict what the climate will be like in the future, scientists must rely on sophisticated computer models. These models use mathematical equations to represent physical processes and interactions in the atmosphere, ocean, and on land. A starting point is usually based on current measurements or estimates of past conditions. Then, using a spherical grid laid out over the entire globe, thousands of calculations are performed at grid intersections to represent and assess how conditions in the air, in the sea, and on land will change over time.Because of their complexity and size, supercomputers are used to run full-scale climate models. Much of the uncertainty in their outputs comes from the way that various aspects of the climate are represented by different models, and even more so, because there are aspects of climate that are not well understood—one of which is how the ocean impacts climate.1.According to paragraph 1, the results of full-scale climate models are questionable in part becauseA.the supercomputers used for such modeling are large and complexB.thousands of calculations have to be performed to assess conditionsC.past conditions cannot always be estimated accuratelyD.there are multiple ways to represent the same aspect of climate Paragraph 2The ocean’s role in global warming stems principally from its huge capacity to absorb carbon dioxide and to store and transport heat. In the sea, photosynthesis by marine plants and algae, especially phytoplankton, removes great quantities of carbon dioxide from the atmosphere. Hence, the greater the growth (productivity) of phytoplankton in the sea, the greater the removal of carbon dioxide. But whatcontrols the ocean’s productivity? There are several limiting factors, but results from a recent experiment suggest that in areas of the ocean where other nutrients are plentiful, iron may be one of the most important and, until recently, unrecognized variables controlling phytoplankton production. Some have proposed a radical, highly controversial and uncertain means to counteract global warming—adding iron to the oceans to induce phytoplankton blooms. Perhaps increased phytoplankton growth would use up a significant amount of carbon dioxide in the atmosphere, but perhaps not, and there might well be side effects that could be detrimental to the ocean ecosystem.2.The word “principally”in the passage is closet in meaning toA.obviouslyB.apparentlyC.mainlyD.originally3.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.A.Iron may be one of the most important factors in controlling phytoplankton production in ocean waters that are rich in other nutrients.B.Results from a recent experiment suggest that several factors limiting phytoplankton production in ocean waters have gone unrecognized.C.Although it was not recognized until recently, nutrients are plentiful in areas of the ocean where iron controls phytoplankton production.D.Until recently, the importance of iron was not taken into account in experiments concerning phytoplankton production.4.The word “controversial”in the passage is closest in meaning toA.experimentalB.fascinatingC.producing disagreementD.demonstrating poor judgment5.The word “induce”in the passage is closest in meaning toA.supply nutrients toB.cause the formation ofC.expandD.strengthen6.According to paragraph 2, how might increasing phytoplankton growth help lower global temperatures?A.By cooling the oceansB.By decreasing carbon dioxide levels in the oceanC.By reducing the amount of carbon dioxide in the atmosphereD.By transporting heat from the ocean’s surface to deeper levelsParagraph 3Within the ocean, the production of limestone, in the form of calcium carbonate skeletons or shells, also reduces atmospheric carbon dioxide. However, when deposits of limestone become exposed and weathered on land or are recycled in the sea, carbon dioxide is released back into the atmosphere. What is not wellunderstood is how much carbon dioxide resides in the sea and at what rate it is taken up and recycled. Relatively new research has also discovered beneath the sea a new and potentially significant threat to skyrocketing Earth temperature: gas hydrates. Gas hydrates are a solid, crystalline form of water, like ice, except that they contain additional gas, typically methane, and are often found stored in ocean sediments. Increased ocean temperatures could cause gas hydrates to dissociate, releasing massive amounts of methane gas into the atmosphere and cause undersea landslides in the process. Consequently, hydrates may, if released, significantly increase global warming as well as create a geologic hazard to offshore drilling operations.7.According to paragraph 3, which of the following reduces atmospheric carbon dioxide?A.The weathering of limestoneB.The production of limestoneC.The recycling of carbon dioxideD.The presence of methane in gas hydrates8.According to paragraph 3, why are gas hydrates a possible threat to the global climate?A.If disturbed by offshore drilling, they can destroy limestone deposits.B.They can replace regular ice at certain locations.C.If melted, they may release a lot of carbon dioxide into the atmosphere.D.They contain a lot of methane, which may be released as the ocean warms Paragraph 4The ocean is also a great reservoir and transporter of heat. Heat from the ocean warms the atmosphere and fuels tropical storms. Heat is transported by currents from the equator to the poles. Ocean circulation is strongly controlled by wind and by the sea’s balance of salt and heat. Scientists think that climate warming may slow down circulation, while cooling may speed it up, but these responses are not well understood. Evaporation from the ocean also supplies the precipitation that creates fields of snow and ice at high latitudes. Snow and ice coverage change the reflectivity Earth’s surface and are an important influence on how much incoming radiation is either absorbed or reflected. Furthermore, clouds and water vapor in the atmosphere come mainly from the sea and strongly influence climate. Surprisingly, clouds are one of the least understood and most poorly modeled parts of the climate change equation. Most climate modeling grids fail to take into account common-sized cloud formations. Aerosols, tiny particles of soot, dust, and other materials, are thought to seed cloud formation scatter incoming radiation and promote cooling, but this effect, which would counteract warming, is also only superficially understood. Computer models of climate change must take into account all of the processes within the ocean, over land, and in the sky that potentially influence warming. No wonder there is such uncertainty.9.The word “fuels”in the passage is closest in meaning toA.provides energy forB.determines the route ofC.carriesD.breaks up10.Which of the following is NOT mentioned in paragraph 4 as a way in which the ocean affects the climate?A.It stores heatB.It moves heat from the equator toward the poles.C.It speeds up wind circulation.D.It warms up the atmosphere.11.Paragraph 4 suggests that a significant decrease in snow and ice fields at high latitudes would have what effect?A.More clouds and water vapor would be produced in the atmosphere.B.More of the Sun’s radiation would be absorbed by Earth.C.The oceans would cool more quickly.D.More precipitation would occur at low latitudes.12.Why does the author mention that “Most climate modeling grids fail to take into account common-sized cloud formations”?A.To suggest why the influence of clouds on climate change is still undeterminedB.To explain why research on climate change does not focus on cloudsC.To help explain why it is unclear whether aerosols have the effect of counteracting warmingD.To explain in part why scientists are uncertain how much incoming radiation is absorbed or reflectedParagraph 3Within the ocean, the production of limestone, in the form of calcium carbonate skeletons or shells, also reduces atmospheric carbon dioxide. ■However, when deposits of limestone become exposed and weathered on land or are recycled in the sea, carbon dioxide is released back into the atmosphere. ■What is not well understood is how much carbon dioxide resides in the sea and at what rate it is taken up and recycled. ■Relatively new research has also discovered beneath the sea a new and potentially significant threat to skyrocketing Earth temperature: gas hydrates. ■Gas hydrates are a solid, crystalline form of water, like ice, except that they contain additional gas, typically methane, and are often found stored in ocean sediments. Increased oceantemperatures could cause gas hydrates to dissociate, releasing massive amounts of methane gas into the atmosphere and cause undersea landslides in the process. Consequently, hydrates may, if released, significantly increase global warming as well as create a geologic hazard to offshore drilling operations.13.Look at the four squares [■] that indicate where the following sentence could be added to the passageNor is carbon dioxide the only gaseous substance in the ocean that may affect climate.Where would the sentence best fit?14.Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selected THREE answer choices that express the most important ideas in the passage. Some sentences 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.The oceans affect the climate in numerous ways, some of which are poorly understood and therefore cannot be accurately modeled in computer climate programs.Answer ChoicesA.Estimates of future conditions are entered into supercomputers to calculate climate possibilities at various places on earth.B.Oceans absorb a great deal of carbon dioxide from the air through limestone production and photosynthesis or phytoplankton.C.Gases are stored in the sea in the form of shells and hydrates, but gases stored in these ways can be recycled to the atmosphere where they may cause warming.D.The ocean's capacity to absorb carbon dioxide remains great despite recent reduction of marine plant nutrients such as iron.E.Ocean circulation is strongly controlled by wind and by the sea s balance or salt and heat.F.The ocean bolds and moves a great deal of heat, and as waterevaporates, it produces clouds, snow, and ice, which all affect global temperatures.参考答案1-5:DCACB6-10:CBDAC11-13:BAC14:BCF文章来源:雷哥托福。

TPO51托福独立写作真题阅读与听力材料及参考范文【雷哥托福】

TPO51托福独立写作真题阅读与听力材料及参考范文【雷哥托福】

TPO51托福独立写作真题阅读与听力材料及参考范文【雷哥托福】托福TPO51独立写作Do you agree or disagree with the following statement?When classmates or colleagues communicate about a project in person instead of by e-mail, they will produce better work for the project.Use specific reasons and examples to support your answer.参考范文:With the convenience of e-mail today, many people have gone from working on projects in person to collaborating over e-mail. Is this a positive change? I do not think so.First of all,while working via e-mail may be convenient for when meeting in person is difficult. E-mails are not conducive to some aspects of collaboration. Group brainstorming, for example, works much better when everybody can voice their ideas in person. Brainstorming is a fast and dynamic process. Ideas are quickly generated and discarded. A brainstorming session might normally take an hour to conduct in person, but the process could drag on for several days over e-mail. Plus, not everybody checks their e-mail consistently, so some people might miss out on parts of the brainstorming process.Second of all, e-mail conveys tone and body language very poorly. Misunderstandings can arise more easily when only using e-mail to collaborate. I remember working on a school project once with classmates I wasn’t close with. We all lived very far apart, so e-mail became our main means of communication.However, because we didn’t really take die time to get to know each other in person, there was a lot of miscommunication. For example, people quickly became annoyed at the group leader because his e-mails sounded like orders. In reality he was a reasonable guy,but he didn’t know any of us so he wanted to be clear and direct about everybody,s responsibilities. If we had simply talked things over in person this never would have been an issue.Granted, today e-mail is a necessary tool in almost any group project. It makes collaborating much more flexible, because groins can stay in touch even when they aren't assembled in one place. But e-mail can't replace working together face-to-face. At best, it can serve as a supplementary tool to keep people updated on projects. Whether it’s brainstorming ideas or rehearsing a presentation, large parts of the collaborative process benefit from having everyone physically present. Not to mention, some people absorb information best when they see and hear explanations. We would never suggest, for example, that teachers teach by sending e-mails instead of lecturing in classrooms. So e-mail may not be the most effective way for people to exchange information during projects, E-mail is a wonderful invention that has changed the way people communicate. However, in some areas of life, it will never be as effective as face-to-face communication. When working on projects, it is still better to collaborate in person.来源:雷哥托福。

托福阅读TPO3(试题+答案+译...

托福阅读TPO3(试题+答案+译...

托福阅读TPO3(试题+答案+译文)第3篇:TheLong-TermStabilityofEcosystems为了帮助大家备考托福。

提高阅读成绩,打有准备的仗,下面小编给大家带来托福阅读TPO3(试题+答案+译文)第3篇:The Long-Term Stability of Ecosystems,希望大家喜欢。

托福阅读原文Plant communities assemble themselvesflexibly, and their particular structure depends on the specific history of thearea. Ecologists use the term “succession” to refer to the changes that happenin plant communities and ecosystems over time. The first community in asuccession is called a pioneer community, while the long-lived community at theend of succession is called a climax community. Pioneer and successional plantcommunities are said to change over periods from 1 to 500 years. Thesechanges—in plant numbers and the mix of species—are cumulative. Climaxcommunities themselves change but over periods of time greater than about 500years.An ecologist who studies a pond today maywell find it relatively unchanged in a year’s time. Individual fish may bereplaced, but the number of fish will tend to be the same from one year to thenext. We can say that the properties of an ecosystem are more stable than theindividual organisms that compose the ecosystem.At one time, ecologists believed that speciesdiversity made ecosystems stable. They believed that the greater the diversitythe more stable the ecosystem. Support for this idea came from the observationthat long-lasting climax communities usually have more complex food webs andmore species diversity than pioneer communities. Ecologists concluded that theapparent stability ofclimax ecosystems depended on their complexity. T o takean extreme example, farmlands dominated by a single crop are so unstable thatone year of bad weather or the invasion of a single pest can destroy the entirecrop. In contrast, a complex climax community, such as a temperate forest, willtolerate considerable damage from weather to pests.The question of ecosystem stability iscomplicated, however. The first problem is that ecologists do not all agreewhat “stability”means. Stability can be defined as simply lack of change. Inthat case, the climax community would be considered the most stable, since, bydefinition, it changes the least over time. Alternatively, stability can bedefined as the speed with which an ecosystem returns to a particular formfollowing a major disturbance, such as a fire. This kind of stability is alsocalled resilience. In that case, climax communities would be the most fragileand the least stable, since they can require hundreds of years to return to theclimax state.Even the kind of stability defined assimple lack of change is not always associated with maximum diversity. At leastin temperate zones, maximum diversity is often found in mid-successionalstages, not in the climax community. Once a redwood forest matures, forexample, the kinds of species and the number of individuals growing on theforest floor are reduced. In general, diversity, by itself, does not ensurestability. Mathematical models of ecosystems likewise suggest that diversitydoes not guarantee ecosystem stability—just the opposite, in fact. A morecomplicated system is, in general, more likely than a simple system to breakdown. A fifteen-speed racing bicycle is more likely to break down than achild’s tricycle.Ecologists are especially interested toknow what factorscontribute to the resilience of communities because climaxcommunities all over the world are being severely damaged or destroyed by humanactivities. The destruction caused by the volcanic explosion of Mount St.Helens, in the northwestern United States, for example, pales in comparison tothe destruction caused by humans. We need to know what aspects of a communityare most important to the community’s resistance to destruction, as well as itsrecovery.Many ecologists now think that the relativelong-term stability of climax communities comes not from diversity but from the“patchiness” of the environment, an environment that varies from place to placesupports more kinds of organisms than an environment that is uniform. A localpopulation that goes extinct is quickly replaced by immigrants from an adjacentcommunity. Even if the new population is of a different species, it canapproximately fill the niche vacated by the extinct population and keep thefood web intact.托福阅读试题1. The word “particular”in the passage(paragraph 1) is closest in meaning toA.naturalB.finalC.specificplex2. According to paragraph 1, which of thefollowing is NOT true of climax communities?A.They occur at the end of a succession.B.They last longer than any other type ofcommunity.C.The numbers of plants in them and the mixof species do not change.D.They remain stable for at least 500 yearsat a time.3. According to paragraph 2, which of thefollowing principles of ecosystems can be learned bystudying a pond?A.Ecosystem properties change more slowlythan individuals in the system.B.The stability of an ecosystem tends tochange as individuals are replaced.C.Individual organisms are stable from oneyear to the next.D.A change in the members of an organismdoes not affect an ecosystem’s properties.4. According to paragraph 3, ecologistsonce believed that which of the following illustratedthe most stableecosystems?A.Pioneer communitiesB.Climax communitiesC.Single-crop farmlandsD.Successional plant communities5. According to paragraph 4, why is thequestion of ecosystem stability complicated?A.The reasons for ecosystem change are notalways clear.B.Ecologists often confuse the word“stability”with the word “resilience.”C.The exact meaning of the word “stability”is debated by ecologists.D.There are many different answers toecological questions.6. According to paragraph 4, which of thefollowing is true of climax communities?A.They are more resilient than pioneercommunities.B.They can be considered both the most andthe least stable communities.C.They are stable because they recoverquickly after majordisturbances.D.They are the most resilient communitiesbecause they change the least over time.7. Which of the following can be inferredfrom paragraph 5 about redwood forests?A.They become less stable as they mature.B.They support many species when they reachclimax.C.They are found in temperate zones.D.They have reduced diversity duringmid-successional stages.8. The word “guarantee”in the passage(paragraph 5) is closest in meaning toA.increaseB.ensureC.favorplicate9. In paragraph 5, why does the authorprovide the information that “A fifteen-speed racing bicycle is more likely tobreak down than a child’s tricycle”?A.To illustrate a general principle aboutthe stability of systems by using an everyday exampleB.To demonstrate that an understanding ofstability in ecosystems can be applied to help understand stability in othersituationsC.To make a comparison that supports theclaim that, in general, stability increases with diversityD.To provide an example that contradictsmathematical models of ecosystems10. The word “pales” in the passage(paragraph 6) is closest in meaning toA.increases proportionallyB.differsC.loses significanceD.is common11. Which of the sentences below bestexpresses the essential information in the highlighted sentence in the passage(paragraph 7)? Incurred choices change the meaning in important ways or leaveout essential information.A.Ecologists now think that the stabilityof an environment is a result of diversity rather than patchiness.B.Patchy environments that vary from placeto place do not often have high species diversity.C.Uniform environments cannot be climaxcommunities because they do not support as many types of organisms as patchyenvironments.D.A patchy environment is thought toincrease stability because it is able to support a wide variety of organisms.12. The word “adjacent”in the passage(paragraph 7) is closest in meaning toA.foreignB.stableC.fluidD.neighboring13. Look at the four squares [█] thatindicate where the following sentence could be added to the passage. In fact,damage to the environment by humans is often much more severe than damage bynatural events and processes.█【A】Ecologists are especially interested to know what factors contributeto the resilience of communities because climax communities all over the worldare being severelydamaged or destroyed by human activities. █【B】The destructioncaused by the volcanic explosion of Mount St. Helens, in the northwesternUnited States, for example, pales in comparison to the destruction caused byhumans. █【C】We need toknow what aspects of a community are most important to the community’sresistance to destruction, as well as its recovery. █【D】Where would the sentence best fit? Click ona square to add the sentence to the passage.14. Directions: Anintroductory sentence for a brief summary of the passage is provided plete the summary by selecting the THREE answer choices that express themost important ideas in the passage. Some sentences do not belong in thesummary because they express ideas that are not presented in the passage or areminor ideas in the passage. This question is worth 2 points.The process of succession and the stabilityof a climax community can change over time.A.The changes that occur in an ecosystemfrom the pioneer to the climax community can be seen in one human generation.B.A high degree of species diversity doesnot always result in a stable ecosystem.C.The level of resilience in a plantcommunity contributes to its long-term stability.D.Ecologists agree that climax communitiesare the most stable types of ecosystems.E.Disagreements over the meaning of theterm “stability”make it difficult to identify the most stable ecosystems.F.The resilience of climax communitiesmakes them resistant to destruction caused by humans.托福阅读答案1. particular特别的,特定的,答案specific。

精品文档TPO51托福阅读passage3:The Role of the Ocean in Controlling Climate原文文本 真题答案

精品文档TPO51托福阅读passage3:The Role of the Ocean in Controlling Climate原文文本 真题答案

TPO51托福阅读passage3:The Role of the Oceanin Controlling Climate原文文本+真题答案第三篇:社会学The Role of the Ocean in Controlling ClimateTo predict what the climate will be like in the future, scientists must rely on sophisticated computer models. These models use mathematical equations to represent physical processes and interactions in the atmosphere, ocean, and on land. A starting point is usually based on current measurements or estimates of past conditions. Then, using a spherical grid laid out over the entire globe,thousands of calculations are performed at grid intersections to represent and assess how conditions in the air, in the sea, and on land will change over time. Because of their complexity and size, supercomputers are used to run full-scale climate models. Much of the uncertainty in their outputs comes from the way that various aspects of the climate are represented by different models, and even more so, because there are aspects of climate that are not well understood—one of which is how the ocean impacts climate.The ocean’s role in global warming stems principally from its huge capacity to absorb carbon dioxide and to store and transport heat. In the sea, photosynthesis by marine plants and algae, especially phytoplankton, removes great quantities of carbon dioxide from the atmosphere. Hence, the greater the growth (productivity) of phytoplankton in the sea, the greater the removal of carbon dioxide. But what controls the ocean’s productivity? There are several limiting factors, but results from a recent experiment suggest that inareas of the ocean where other nutrients are plentiful, iron may be one of the most important and, until recently, unrecognized variables controlling phytoplankton production. Some have proposed a radical, highly controversial and uncertain means to counteract global warming —adding iron to the oceans to induce phytoplankton blooms. Perhaps increased phytoplankton growth would use up a significant amount of carbon dioxide in the atmosphere, but perhaps not, and there might well be side effects that could be detrimental to the ocean ecosystem.Within the ocean, the production of limestone, in the form of calcium carbonate skeletons or shells, also reduces atmospheric carbon dioxide. However, when deposits of limestone become exposed and weathered on land or are recycled in the sea, carbon dioxide is released back into the atmosphere. What is not well understood is how much carbon dioxide resides in the sea and at what rate it is taken up and recycled. Relatively new research has also discovered beneath the sea a new and potentially significant threat to skyrocketing Earth temperature: gas hydrates. Gas hydrates are a solid, crystalline form of water, like ice, except that they contain additional gas, typically methane, and are often found stored in ocean sediments. Increased ocean temperatures could cause gas hydrates to dissociate, releasing massive amounts of methane gas into the atmosphere and cause undersea landslides in the process. Consequently, hydrates may, if released, significantly increase global warming as well as create a geologic hazard to offshore drilling operations.The ocean is also a great reservoir and transporter of heat. Heat from the ocean warms the atmosphere and fuels tropical storms. Heat is transported by currents from the equator to the poles. Ocean circulation is strongly controlled by wind and by the sea’s balance of salt and heat. Scientists think that climate warming may slow down circulation, while cooling may speed it up, but these responses are not well understood. Evaporation from the ocean also supplies theprecipitation that creates fields of snow and ice at high latitudes. Snow and ice coverage change thereflectivity Earth’s surface and are an important influence on how much incoming radiation is either absorbed or reflected. Furthermore, clouds and water vapor in the atmosphere come mainly from the sea and strongly influence climate. Surprisingly, clouds are one of the least understood and most poorly modeled parts of the climate change equation. Most climate modeling grids fail to take into account common-sized cloud formations. Aerosols, tiny particles of soot, dust, and other materials, are thought to seed cloud formation scatter incoming radiation and promote cooling, but this effect, which would counteract warming, is also only superficially understood. Computer models of climate change must take into account all of the processes within the ocean, over land, and in the sky that potentially influence warming. No wonder there is such uncertainty.题目Paragraph 1To predict what the climate will be like in the future, scientists must rely on sophisticated computer models. These models use mathematical equations to represent physical processes and interactions in the atmosphere, ocean, and on land. A starting point is usually based on current measurements or estimates of past conditions. Then, using a spherical grid laid out over the entire globe, thousands of calculations are performed at grid intersections to represent and assess how conditions in the air, in the sea, and on land will change over time.Because of their complexity and size, supercomputers are used to run full-scale climate models. Much of the uncertainty in their outputs comes from the way that various aspects of the climate are represented by different models, and even more so, because there are aspects ofclimate that are not well understood—one of which is how the ocean impacts climate.1.According to paragraph 1, the results of full-scale climate models are questionable in part becauseA.the supercomputers used for such modeling are large and complexB.thousands of calculations have to be performed to assess conditionsC.past conditions cannot always be estimated accuratelyD.there are multiple ways to represent the same aspect of climate Paragraph 2The ocean’s role in global warming stems principally from its huge capacity to absorb carbon dioxide and to store and transport heat. In the sea, photosynthesis by marine plants and algae, especially phytoplankton, removes great quantities of carbon dioxide from the atmosphere. Hence, the greater the growth (productivity) of phytoplankton in the sea, the greater the removal of carbon dioxide. But whatcontrols the ocean’s productivity? There are several limiting factors, but results from a recent experiment suggest that in areas of the ocean where other nutrients are plentiful, iron may be one of the most important and, until recently, unrecognized variables controlling phytoplankton production. Some have proposed a radical, highly controversial and uncertain means to counteract global warming—adding iron to the oceans to induce phytoplankton blooms. Perhaps increased phytoplankton growth would use up a significant amount of carbon dioxide in the atmosphere, but perhaps not, and there might well be side effects that could be detrimental to the ocean ecosystem.2.The word “principally”in the passage is closet in meaning toA.obviouslyB.apparentlyC.mainlyD.originally3.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.A.Iron may be one of the most important factors in controlling phytoplankton production in ocean waters that are rich in other nutrients.B.Results from a recent experiment suggest that several factors limiting phytoplankton production in ocean waters have gone unrecognized.C.Although it was not recognized until recently, nutrients are plentiful in areas of the ocean where iron controls phytoplankton production.D.Until recently, the importance of iron was not taken into account in experiments concerning phytoplankton production.4.The word “controversial”in the passage is closest in meaning toA.experimentalB.fascinatingC.producing disagreementD.demonstrating poor judgment5.The word “induce”in the passage is closest in meaning toA.supply nutrients toB.cause the formation ofC.expandD.strengthen6.According to paragraph 2, how might increasing phytoplanktongrowth help lower global temperatures?A.By cooling the oceansB.By decreasing carbon dioxide levels in the oceanC.By reducing the amount of carbon dioxide in the atmosphereD.By transporting heat from the ocean’s surface to deeper levels Paragraph 3Within the ocean, the production of limestone, in the form of calcium carbonate skeletons or shells, also reduces atmospheric carbon dioxide. However, when deposits of limestone become exposed and weathered on land or are recycled in the sea, carbon dioxide is released back into the atmosphere. What is not wellunderstood is how much carbon dioxide resides in the sea and at what rate it is taken up and recycled. Relatively new research has also discovered beneath the sea a new and potentially significant threat to skyrocketing Earth temperature: gas hydrates. Gas hydrates are a solid, crystalline form of water, like ice, except that they contain additional gas, typically methane, and are often found stored in ocean sediments. Increased ocean temperatures could cause gas hydrates to dissociate, releasing massive amounts of methane gas into the atmosphere and cause undersea landslides in the process. Consequently, hydrates may, if released, significantly increase global warming as well as create a geologic hazard to offshore drilling operations.7.According to paragraph 3, which of the following reduces atmospheric carbon dioxide?A.The weathering of limestoneB.The production of limestoneC.The recycling of carbon dioxideD.The presence of methane in gas hydrates8.According to paragraph 3, why are gas hydrates a possible threat to the global climate?A.If disturbed by offshore drilling, they can destroy limestone deposits.B.They can replace regular ice at certain locations.C.If melted, they may release a lot of carbon dioxide into the atmosphere.D.They contain a lot of methane, which may be released as the ocean warms Paragraph 4The ocean is also a great reservoir and transporter of heat. Heat from the ocean warms the atmosphere and fuels tropical storms. Heat is transported by currents from the equator to the poles. Ocean circulation is strongly controlled by wind and by the sea’s balance of salt and heat. Scientists think that climate warming may slow down circulation, while cooling may speed it up, but these responses are not well understood. Evaporation from the ocean also supplies the precipitation that creates fields of snow and ice at high latitudes. Snow and ice coverage change the reflectivity Earth’s surface and are an important influence on how much incoming radiation is either absorbed or reflected. Furthermore, clouds and water vapor in the atmosphere come mainly from the sea and strongly influence climate. Surprisingly, clouds are one of the least understood and most poorly modeled parts of the climate change equation. Most climate modeling grids fail to take into account common-sized cloud formations. Aerosols, tiny particles of soot, dust, and other materials, are thought to seed cloud formation scatter incoming radiation and promote cooling, but this effect, which would counteract warming, is also only superficially understood. Computer models of climate change must take into account all of the processes within the ocean, over land, and in the sky that potentially influence warming. No wonder there is such uncertainty.9.The word “fuels”in the passage is closest in meaning toA.provides energy forB.determines the route ofC.carriesD.breaks up10.Which of the following is NOT mentioned in paragraph 4 as a way in which the ocean affects the climate?A.It stores heatB.It moves heat from the equator toward the poles.C.It speeds up wind circulation.D.It warms up the atmosphere.11.Paragraph 4 suggests that a significant decrease in snow and ice fields at high latitudes would have what effect?A.More clouds and water vapor would be produced in the atmosphere.B.More of the Sun’s radiation would be absorbed by Earth.C.The oceans would cool more quickly.D.More precipitation would occur at low latitudes.12.Why does the author mention that “Most climate modeling grids fail to take into account common-sized cloud formations”?A.To suggest why the influence of clouds on climate change is still undeterminedB.To explain why research on climate change does not focus on cloudsC.To help explain why it is unclear whether aerosols have the effect of counteracting warmingD.To explain in part why scientists are uncertain how much incoming radiation is absorbed or reflectedParagraph 3Within the ocean, the production of limestone, in the form of calcium carbonate skeletons or shells, also reduces atmospheric carbon dioxide. ■However, when deposits of limestone become exposed andweathered on land or are recycled in the sea, carbon dioxide is released back into the atmosphere. ■What is not well understood is how much carbon dioxide resides in the sea and at what rate it is taken up and recycled. ■Relatively new research has also discovered beneath the sea a new and potentially significant threat to skyrocketing Earth temperature: gas hydrates. ■Gas hydrates are a solid, crystalline form of water, like ice, except that they contain additional gas, typically methane, and are often found stored in ocean sediments. Increased ocean temperatures could cause gas hydrates to dissociate, releasing massive amounts of methane gas into the atmosphere and cause undersea landslides in the process. Consequently, hydrates may, if released, significantly increase global warming as well as create a geologic hazard to offshore drilling operations.13.Look at the four squares [■] that indicate where the following sentence could be added to the passageNor is carbon dioxide the only gaseous substance in the ocean that may affect climate.Where would the sentence best fit?14.Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selected THREE answer choices that express the most important ideas in the passage. Some sentences 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.The oceans affect the climate in numerous ways, some of which are poorly understood and therefore cannot be accurately modeled in computer climate programs.Answer ChoicesA.Estimates of future conditions are entered into supercomputers to calculate climate possibilities at various places on earth.B.Oceans absorb a great deal of carbon dioxide from the air throughlimestone production and photosynthesis or phytoplankton.C.Gases are stored in the sea in the form of shells and hydrates, but gases stored in these ways can be recycled to the atmosphere where they may cause warming.D.The ocean's capacity to absorb carbon dioxide remains great despite recent reduction of marine plant nutrients such as iron.E.Ocean circulation is strongly controlled by wind and by the sea s balance or salt and heat.F.The ocean bolds and moves a great deal of heat, and as water evaporates, it produces clouds, snow, and ice, which all affect global temperatures.参考答案1-5:DCACB6-10:CBDAC11-13:BAC14:BCF文章来源:雷哥托福倚窗远眺,目光目光尽处必有一座山,那影影绰绰的黛绿色的影,是春天的颜色。

托福阅读tpo51R-3原文+译文+题目+答案+背景知识

托福阅读tpo51R-3原文+译文+题目+答案+背景知识

TPO51阅读-3Population Growth in Nineteenth-Century Europe原文 (1)译文 (2)题目 (4)答案 (8)背景知识 (9)原文Population Growth in Nineteenth-Century Europe①Because of industrialization,but also because of a vast increase in agricultural output without which industrialization would have been impossible,Western Europeans by the latter half of the nineteenth century enjoyed higher standards of living and longer,healthier lives than most of the world’s peoples.In Europe as a whole,the population rose from188million in1800to400million in1900.By 1900,virtually every area of Europe had contributed to the tremendous surge of population,but each major region was at a different stage of demographic change.②Improvements in the food supply continued trends that had started in the late seventeenth century.New lands were put under cultivation,while the use of crops of American origin,particularly the potato,continued to expand.Setbacks did occur.Regional agricultural failures were the most common cause of economic recessions until1850,and they could lead to localized famine as well.A major potato blight(disease)in1846-1847led to the deaths of at least one million persons in Ireland and the emigration of another million,and Ireland never recovered the population levels the potato had sustained to that point.Bad grain harvests at the same time led to increased hardship throughout much of Europe.③After1850,however,the expansion of foods more regularly kept pace with population growth,though the poorer classes remained malnourished.Two developments were crucial.First,the application of science and new technology to agriculture increased.Led by German universities,increasing research was devoted to improving seeds,developing chemical fertilizers,and advancing livestock.After 1861,with the development of land-grant universities in the United States that had huge agricultural programs,American crop-production research added to this mix. Mechanization included the use of horse-drawn harvesters and seed drills,many developed initially in the United States.It also included mechanical cream separators and other food-processing devices that improved supply.④The second development involved industrially based transportation.With trains and steam shipping,it became possible to move foods to needy regions withinWestern Europe quickly.Famine(as opposed to malnutrition)became a thing of the past.Many Western European countries,headed by Britain,began also to import increasing amounts of food,not only from Eastern Europe,a traditional source,but also from the Americas,Australia,and New Zealand.Steam shipping, which improved speed and capacity,as well as new procedures for canning and refrigerating foods(particularly after1870),was fundamental to these developments.⑤Europe's population growth included one additional innovation by the nineteenth century:it combined with rapid urbanization.More and more Western Europeans moved from countryside to city,and big cities grew most rapidly of all. By1850,over half of all the people in England lived in cities,a first in human history.In one sense,this pattern seems inevitable growing numbers of people pressed available resources on the land,even when farmwork was combined with a bit of manufacturing,so people crowded into cities seeking work or other resources.Traditionally,however,death rates in cities surpassed those in the countryside by a large margin;cities had maintained population only through steady in-migration.Thus rapid urbanization should have reduced overall population growth,but by the middle of the nineteenth century this was no longer the case.Urban death rates remained high,particularly in the lower-class slums, but they began to decline rapidly.⑥The greater reliability of food supplies was a factor in the decline of urban death rates.Even more important were the gains in urban sanitation,as well as measures such as inspection of housing.Reformers,including enlightened doctors,began to study the causes of high death rates and to urge remediation.Even before the discovery of germs,beliefs that disease spread by"miasmas"(noxious forms of bad air)prompted attention to sewers and open garbage;Edwin Chadwick led an exemplary urban crusade for underground sewers in England in the1830s. Gradually,public health provisions began to cut into customary urban mortality rates.By1900,in some parts of Western Europe life expectancy in the cities began to surpass that of the rural areas.Industrial societies had figured out ways to combine large and growing cities with population growth,a development that would soon spread to other parts of the world.译文十九世纪欧洲的人口增长①由于工业化,也由于农业产量的大幅度增加(如果没有这些就不可能实现工业化),西欧人到了十九世纪后半叶比世界上大多数民族享有更高的生活水平和更长寿,更健康的生活。

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TPO51托福阅读passage3:The Role of the Oceanin Controlling Climate原文文本+真题答案第三篇:社会学The Role of the Ocean in Controlling ClimateTo predict what the climate will be like in the future, scientists must rely on sophisticated computer models. These models use mathematical equations to represent physical processes and interactions in the atmosphere, ocean, and on land. A starting point is usually based on current measurements or estimates of past conditions. Then, using a spherical grid laid out over the entire globe,thousands of calculations are performed at grid intersections to represent and assess how conditions in the air, in the sea, and on land will change over time. Because of their complexity and size, supercomputers are used to run full-scale climate models. Much of the uncertainty in their outputs comes from the way that various aspects of the climate are represented by different models, and even more so, because there are aspects of climate that are not well understood—one of which is how the ocean impacts climate.The ocean’s role in global warming stems principally from its huge capacity to absorb carbon dioxide and to store and transport heat. In the sea, photosynthesis by marine plants and algae, especially phytoplankton, removes great quantities of carbon dioxide from the atmosphere. Hence, the greater the growth (productivity) of phytoplankton in the sea, the greater the removal of carbon dioxide. But what controls the ocean’s productivity? There are several limiting factors, but results from a recent experiment suggest that in areas of the ocean where other nutrients are plentiful, iron may be one ofthe most important and, until recently, unrecognized variables controlling phytoplankton production. Some have proposed a radical, highly controversial and uncertain means to counteract global warming —adding iron to the oceans to induce phytoplankton blooms. Perhaps increased phytoplankton growth would use up a significant amount of carbon dioxide in the atmosphere, but perhaps not, and there might well be side effects that could be detrimental to the ocean ecosystem.Within the ocean, the production of limestone, in the form of calcium carbonate skeletons or shells, also reduces atmospheric carbon dioxide. However, when deposits of limestone become exposed and weathered on land or are recycled in the sea, carbon dioxide is released back into the atmosphere. What is not well understood is how much carbon dioxide resides in the sea and at what rate it is taken up and recycled. Relatively new research has also discovered beneath the sea a new and potentially significant threat to skyrocketing Earth temperature: gas hydrates. Gas hydrates are a solid, crystalline form of water, like ice, except that they contain additional gas, typically methane, and are often found stored in ocean sediments. Increased ocean temperatures could cause gas hydrates to dissociate, releasing massive amounts of methane gas into the atmosphere and cause undersea landslides in the process. Consequently, hydrates may, if released, significantly increase global warming as well as create a geologic hazard to offshore drilling operations.The ocean is also a great reservoir and transporter of heat. Heat from the ocean warms the atmosphere and fuels tropical storms. Heat is transported by currents from the equator to the poles. Ocean circulation is strongly controlled by wind and by the sea’s balance of salt and heat. Scientists think that climate warming may slow down circulation, while cooling may speed it up, but these responses are not well understood. Evaporation from the ocean also supplies the precipitation that creates fields of snow and ice at high latitudes. Snow and ice coverage change thereflectivity Earth’s surface and are an important influence on how much incoming radiation is either absorbed or reflected. Furthermore, clouds and water vapor in the atmosphere come mainly from the sea and strongly influence climate. Surprisingly, clouds are one of the least understood and most poorly modeled parts of the climate change equation. Most climate modeling grids fail to take into account common-sized cloud formations. Aerosols, tiny particles of soot, dust, and other materials, are thought to seed cloud formation scatter incoming radiation and promote cooling, but this effect, which would counteract warming, is also only superficially understood. Computer models of climate change must take into account all of the processes within the ocean, over land, and in the sky that potentially influence warming. No wonder there is such uncertainty.题目Paragraph 1To predict what the climate will be like in the future, scientists must rely on sophisticated computer models. These models use mathematical equations to represent physical processes and interactions in the atmosphere, ocean, and on land. A starting point is usually based on current measurements or estimates of past conditions. Then, using a spherical grid laid out over the entire globe, thousands of calculations are performed at grid intersections to represent and assess how conditions in the air, in the sea, and on land will change over time.Because of their complexity and size, supercomputers are used to run full-scale climate models. Much of the uncertainty in their outputs comes from the way that various aspects of the climate are represented by different models, and even more so, because there are aspects of climate that are not well understood—one of which is how the ocean impacts climate.1.According to paragraph 1, the results of full-scale climate models are questionable in part becauseA.the supercomputers used for such modeling are large and complexB.thousands of calculations have to be performed to assess conditionsC.past conditions cannot always be estimated accuratelyD.there are multiple ways to represent the same aspect of climate Paragraph 2The ocean’s role in global warming stems principally from its huge capacity to absorb carbon dioxide and to store and transport heat. In the sea, photosynthesis by marine plants and algae, especially phytoplankton, removes great quantities of carbon dioxide from the atmosphere. Hence, the greater the growth (productivity) of phytoplankton in the sea, the greater the removal of carbon dioxide. But whatcontrols the ocean’s productivity? There are several limiting factors, but results from a recent experiment suggest that in areas of the ocean where other nutrients are plentiful, iron may be one of the most important and, until recently, unrecognized variables controlling phytoplankton production. Some have proposed a radical, highly controversial and uncertain means to counteract global warming—adding iron to the oceans to induce phytoplankton blooms. Perhaps increased phytoplankton growth would use up a significant amount of carbon dioxide in the atmosphere, but perhaps not, and there might well be side effects that could be detrimental to the ocean ecosystem.2.The word “principally”in the passage is closet in meaning toA.obviouslyB.apparentlyC.mainlyD.originally3.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.A.Iron may be one of the most important factors in controlling phytoplankton production in ocean waters that are rich in other nutrients.B.Results from a recent experiment suggest that several factors limiting phytoplankton production in ocean waters have gone unrecognized.C.Although it was not recognized until recently, nutrients are plentiful in areas of the ocean where iron controls phytoplankton production.D.Until recently, the importance of iron was not taken into account in experiments concerning phytoplankton production.4.The word “controversial”in the passage is closest in meaning toA.experimentalB.fascinatingC.producing disagreementD.demonstrating poor judgment5.The word “induce”in the passage is closest in meaning toA.supply nutrients toB.cause the formation ofC.expandD.strengthen6.According to paragraph 2, how might increasing phytoplankton growth help lower global temperatures?A.By cooling the oceansB.By decreasing carbon dioxide levels in the oceanC.By reducing the amount of carbon dioxide in the atmosphereD.By transporting heat from the ocean’s surface to deeper levelsParagraph 3Within the ocean, the production of limestone, in the form of calcium carbonate skeletons or shells, also reduces atmospheric carbon dioxide. However, when deposits of limestone become exposed and weathered on land or are recycled in the sea, carbon dioxide is released back into the atmosphere. What is not wellunderstood is how much carbon dioxide resides in the sea and at what rate it is taken up and recycled. Relatively new research has also discovered beneath the sea a new and potentially significant threat to skyrocketing Earth temperature: gas hydrates. Gas hydrates are a solid, crystalline form of water, like ice, except that they contain additional gas, typically methane, and are often found stored in ocean sediments. Increased ocean temperatures could cause gas hydrates to dissociate, releasing massive amounts of methane gas into the atmosphere and cause undersea landslides in the process. Consequently, hydrates may, if released, significantly increase global warming as well as create a geologic hazard to offshore drilling operations.7.According to paragraph 3, which of the following reduces atmospheric carbon dioxide?A.The weathering of limestoneB.The production of limestoneC.The recycling of carbon dioxideD.The presence of methane in gas hydrates8.According to paragraph 3, why are gas hydrates a possible threat to the global climate?A.If disturbed by offshore drilling, they can destroy limestone deposits.B.They can replace regular ice at certain locations.C.If melted, they may release a lot of carbon dioxide into the atmosphere.D.They contain a lot of methane, which may be released as the ocean warms Paragraph 4The ocean is also a great reservoir and transporter of heat. Heat from the ocean warms the atmosphere and fuels tropical storms. Heat is transported by currents from the equator to the poles. Ocean circulation is strongly controlled by wind and by the sea’s balance of salt and heat. Scientists think that climate warming may slow down circulation, while cooling may speed it up, but these responses are not well understood. Evaporation from the ocean also supplies the precipitation that creates fields of snow and ice at high latitudes. Snow and ice coverage change the reflectivity Earth’s surface and are an important influence on how much incoming radiation is either absorbed or reflected. Furthermore, clouds and water vapor in the atmosphere come mainly from the sea and strongly influence climate. Surprisingly, clouds are one of the least understood and most poorly modeled parts of the climate change equation. Most climate modeling grids fail to take into account common-sized cloud formations. Aerosols, tiny particles of soot, dust, and other materials, are thought to seed cloud formation scatter incoming radiation and promote cooling, but this effect, which would counteract warming, is also only superficially understood. Computer models of climate change must take into account all of the processes within the ocean, over land, and in the sky that potentially influence warming. No wonder there is such uncertainty.9.The word “fuels”in the passage is closest in meaning toA.provides energy forB.determines the route ofC.carriesD.breaks up10.Which of the following is NOT mentioned in paragraph 4 as a way in which the ocean affects the climate?A.It stores heatB.It moves heat from the equator toward the poles.C.It speeds up wind circulation.D.It warms up the atmosphere.11.Paragraph 4 suggests that a significant decrease in snow and ice fields at high latitudes would have what effect?A.More clouds and water vapor would be produced in the atmosphere.B.More of the Sun’s radiation would be absorbed by Earth.C.The oceans would cool more quickly.D.More precipitation would occur at low latitudes.12.Why does the author mention that “Most climate modeling grids fail to take into account common-sized cloud formations”?A.To suggest why the influence of clouds on climate change is still undeterminedB.To explain why research on climate change does not focus on cloudsC.To help explain why it is unclear whether aerosols have the effect of counteracting warmingD.To explain in part why scientists are uncertain how much incoming radiation is absorbed or reflectedParagraph 3Within the ocean, the production of limestone, in the form of calcium carbonate skeletons or shells, also reduces atmospheric carbon dioxide. ■However, when deposits of limestone become exposed and weathered on land or are recycled in the sea, carbon dioxide is released back into the atmosphere. ■What is not well understood is how much carbon dioxide resides in the sea and at what rate it is taken up and recycled. ■Relatively new research has also discovered beneath the sea a new and potentially significant threat to skyrocketing Earth temperature: gas hydrates. ■Gas hydrates are a solid, crystalline form of water, like ice, except that they contain additional gas, typically methane, and are often found stored in ocean sediments. Increased oceantemperatures could cause gas hydrates to dissociate, releasing massive amounts of methane gas into the atmosphere and cause undersea landslides in the process. Consequently, hydrates may, if released, significantly increase global warming as well as create a geologic hazard to offshore drilling operations.13.Look at the four squares [■] that indicate where the following sentence could be added to the passageNor is carbon dioxide the only gaseous substance in the ocean that may affect climate.Where would the sentence best fit?14.Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selected THREE answer choices that express the most important ideas in the passage. Some sentences 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.The oceans affect the climate in numerous ways, some of which are poorly understood and therefore cannot be accurately modeled in computer climate programs.Answer ChoicesA.Estimates of future conditions are entered into supercomputers to calculate climate possibilities at various places on earth.B.Oceans absorb a great deal of carbon dioxide from the air through limestone production and photosynthesis or phytoplankton.C.Gases are stored in the sea in the form of shells and hydrates, but gases stored in these ways can be recycled to the atmosphere where they may cause warming.D.The ocean's capacity to absorb carbon dioxide remains great despite recent reduction of marine plant nutrients such as iron.E.Ocean circulation is strongly controlled by wind and by the sea s balance or salt and heat.F.The ocean bolds and moves a great deal of heat, and as waterevaporates, it produces clouds, snow, and ice, which all affect global temperatures.参考答案1-5:DCACB6-10:CBDAC11-13:BAC14:BCF文章来源:雷哥托福。

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