【威学教育】王鑫托福阅读TPO15-2阅读文本
【王鑫托福阅读】托福TPO 15-2阅读文本
TPO 15
TPO15-2 Mass Extinctions
D Fossil records disappeared.
of many marine species have
1. Paragraph 1 supports which of the following statements about mass extinctions?
A They take place over a period of 70 million years.
B They began during the Cretaceous period.
C They eliminate many animal species that exist at the time they occur.
D They occur every 250 million years.
2. According to paragraph 2, scientists base their belief that a mass extinction is going on at present on which of the following?
A The speed with which mass extinctions are happening today is similar to the speed of past extinctions.
B The number of species that have died out since the last extinction event is extremely large.
C Mass extinctions occur with regularity and it is time fo「a门othe「one.
Cases in which many species become extinct within a geologically short interval of time are called mass extinctions. There was one such event at the end of the Cretaceous period (around 70 million years ago). There was another,
even larger, mass extinction at the end of the Permian period (around 250 million years ago). The Permian event has attracted much less attention than other mass extinctions because mostly unfamiliar species perished at that time.
The fossil record shows at least five mass extinctions in which many families of marine organisms died out. The rates of extinction happening today are as great as the rates during these mass extinctions. Many scientists have therefore concluded that a sixth great mass extinction is currently in progress.
3. The word extended in the passage is closest in meaning to
A specific
B unlimited
C reasonable
D long
4. According to paragraph 3, each of the following has been proposed as
a possible cause of mass extinctions EXCEPT
A habitat destruction
B continental movement
C fierce interspecies competition
D changes in Earth's temperature
5. Paragraph 3 supports which of the following ideas about mass extinctions?
A Scientists know the exact causes of most mass extinctions.
B Mass extinctions are unlikely to happen again in the future.
C Insects, flowering plants, and bottom-feeding predators in the oceans tend to be the first organisms to disappear during episodes of mass extinctions.
D Some mass extinctions occurred on land and in the seas at the same time.
What could cause such high rates of extinction? There are several hypotheses, including warming or cooling of Earth, changes in seasonal fluctuations or ocean currents, and changing positions of the continents. Biological hypotheses include ecological changes brought about by the evolution of cooperation between insects and flowering plants or of bottom-feeding predators in the oceans. Some of the proposed mechanisms required a very brief
period during which all extinctions suddenly took place; other mechanisms would be more likely to have taken place more gradually, over an extended period, or at different times on different continents. Some hypotheses fail to account for simultaneous extinctions on land and in the seas. Each mass extinction may have had a different cause. Evidence points to hunting by humans and habitat destruction as the likely causes for the current mass extinction.
7. According to paragraph 4, what aspect of extinction episodes does the companion-star hypothesis supposedly clarify?
A Their location
B Their frequency
C Their duration
D Their severity
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.
A Based on their studies of extinction rates of numerous fossil groups, paleontologists David Raup and John Sepkoski have determined that mass extinctions occur about every 26 million years.
B David Raup and John Sepkoski studied extinction rates of numerous fossil groups and suggest that mass extinctions during the Cretaceous period continued for 26 million years.
C Studies that paleontologists David Raup and John Sepkoski conducted of various fossil groups have revealed that extinction rates have increased over the past 26 million years.
D The studies conducted by paleontologists David Raup and John Sepkoski of the fossil remains of species suggest that the extinction rate of species started to increase by the middle of the Cretaceous period.
American paleontologists David Raup and John
Sepkoski, who havestudied extinctionrates in a
number of fossil groups, suggest thatepisodes of
increased extinctionhave recurredperiodically,
approximately every26 million yearssince the
mid-Cretaceous period. The late Cretaceous extinction
of the dinosaurs and ammonoids was just one of the more drastic in a whole series of such recurrent extinction episodes. The possibility that mass extinctions may recur periodically has given rise to such hypotheses as that of a companion star with a long-period orbit deflecting other bodies from their normal orbits, making some of them fall to Earth as meteors and causing widespread devastation upon impact.
2. The phrase account for in the passage is closest in meaning to A describe
B challenge
C explain
D test
3. According to paragraph 6, what made iridium a useful test of the Alvarez hypothesis?
A Its occurrence in a few locations on Earth against several locations on other planets
B Its occurrence in limited quantities on Earth against its abundance in asteroids
C Its ability to remain solid at extremely high temperatures
D Its ease of detection even in very small amounts
recovered,
10.In stating that no asteroid itself has ever been the author emphasizes which of the following?
A The importance of the indirect evidence for a large asteroid
B The fact that no evidence supports the asteroid impact hypothesis
C The reason many researchers reject the Alvarez hypothesis
D The responsibility of scientists for not making the effort to discover the asteroid itself
asteroid-impact hypothesis first suggested by Luis and Walter Alvarez. According to this hypothesis, Earth collided with an asteroid with an estimated diameter of 10 kilometers, or with several asteroids, the combined mass of which was comparable. The force of collision spewed large amounts of debris into the atmosphere, darkening the skies for several years before the finer particles settled. The reduced level of photosynthesis led to a massive decline in plant life of all kinds, and this caused massive starvation first of herbivores and subsequently of carnivores. The mass extinction would have occurred very suddenly under this hypothesis.
One interesting test of the Alvarez hypothesis is based on the presence of the rare-earth element iridium (Ir). Earth's crust contains very little of this element, but most asteroids contain a lot more. Debris thrown into the atmosphere by an asteroid collision would presumably contain large amounts of iridium, and atmospheric currents would carry this material all over the globe. A search of sedimentary deposits that span the boundary between the Cretaceous and Tertiary periods shows that there is a dramatic increase in the abundance of iridium briefly and precisely at this boundary. This iridium anomaly offers strong support for the Alvarez hypothesis even though no asteroid itself has ever been recovered.
Of the various hypotheses attempting to account for the late Cretaceous extinctions, the one that has attracted the most attention in recent years is the
11. The word intense in the passage is closest in meaning to A sudden
B unusual
C immediate
D extreme
12. What is the purpose of paragraph 7 in the passage? A It proposes a decisive new test of the Alvarez hypothesis.
B It presents additional supporting evidence for the Alvarez hypothesis.
C It explains why evidence relating to the Alvarez hypothesis is hard to find.
D It shows how recent evidence has raised doubts about the Alvarez hypothesis.
impact would produce heat-shocked quartz in many types of rock. Also, large blocks thrown aside by the impact would form secondary craters surrounding the main crater. To date, several such secondary craters have been found along Mexico's Yucatan Peninsula, and heat-shocked quartz has been found both in Mexico and in Haiti. A location called Chicxulub, along the Yucatan coast, has been suggested as the primary impact site.
■ Cases in which many species become extinct within a extinctions. I There was one such event at the end of the
An asteroid of this size would be expected to leave an immense crater, even if the asteroid itself was disintegrated by the impact. The intense heat of the
geologically short interval Cretaceous period (around
of time are called mass 70 million years ago). |
There was another, even larger, mass extinction at the end of the Permian period (around 250 million years ago). I The Permian event has attracted much less attention than other mass extinctions because mostly unfamiliar species perished at that time.
13. Look at the fou r squares [ ■ ] that indicate where the following sentence could be added to the passage. Where would the sentence best fit?
In general, it is believed that these two extinctions resulted from drastic environmental changes that followed meteorite impacts or massive volcanic eruptions.
14. 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 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. There have been many attempts to explain the causes of mass extinctions.
A. Asteroid impacts, evolutionary developments, and changes in Earth's climate and in the positions of the continents have all been proposed as possible causes of mass extinctions.
B. Researchers have observed 26-million-year cycles in extinction rates of a number of fossil groups that could all be attributed to the same cause.
C. According to the Alvarez hypothesis, much of the iridium originally present on Earth was thrown into the atmosphere as a result of an asteroid impact that also caused a mass extinction.
D. The unusual distribution of iridium on Earth and the presence of craters and heat-shocked quartz are central to the theory that an asteroid impact caused the late Cretaceous event.
E. The collision between Earth and a large asteroid resulted in massive damage and generated enough heat to cause irreversible changes in Earth's atmosphere.
F. There was a particularly large mass extinction that occurred around 250 million years ago at the end of the Permian period, whose cause could not be determined.
【威学教育】王鑫托福阅读TPO5-2阅读文本
【王鑫托福阅读】托福TPO5-2阅读文本 TPO5 TPO5-2 The Origin of the Pacific Island People 1. According to paragraph 1, all of the following are true statements about Melanesia, Micronesia, and Polynesia EXCEPT: A. Collectively, these regions are traditionally known as Oceania. B. These islands of Micronesia are small and spread out. C. Hawaii, Easter Island, and New Zealand mark the boundaries of Polynesia. D. Melanesia is situated to the north of Micronesia. The greater Pacific region, traditionally called Oceania, consists of three cultural areas: Melanesia, Micronesia, and Polynesia. Melanesia, in the southwest Pacific, contains the large islands of New Guinea, the Solomons, Vanuatu, and New Caledonia. Micronesia, the area north of Melanesia, consists primarily of small scattered islands. Polynesia is the central Pacific area in the great triangle defined by Hawaii, Easter Island, and New Zealand. Before the arrival of Europeans, the islands in the two largest cultural areas, Polynesia and Micronesia, together contained a population estimated at 700,000. 2. By stating that the the ories are "mutually exclusive” the author means that A.if one of the theories is true, then all the others must be false B. the differences between the theories are unimportant C. taken together, the theories cover all possibilities D. the theories support each other
【威学教育】王鑫托福阅读TPO23-3阅读文本
【王鑫托福阅读】托福TPO全集之TPO23-3 TPO23 TPO23-3 Rock Art of the Australia Aborigines 1. The word "infrequent”in the passage is closest in meaning to A. puzzling B. uncommon C. questionable D. undocumented 2. According to paragraph 1, the twentieth-century approach to studying Australian rock art was different from earlier approaches because the twentieth-century approach A. recognized that many different groups of Aborigines created Australian rock art B. concentrated on a limited range of Aboriginal rock art C. examined Aboriginal art from an Aboriginal rather than from a European perspective D. focused more intensely on understanding and documenting rock art 3. The word "rela tively”in the passage is closest in meaning to A. completely B. comparatively
【威学教育】王鑫托福阅读TPO15-2阅读文本
【王鑫托福阅读】托福TPO 15-2阅读文本 TPO 15 TPO15-2 Mass Extinctions D Fossil records disappeared. of many marine species have 1. Paragraph 1 supports which of the following statements about mass extinctions? A They take place over a period of 70 million years. B They began during the Cretaceous period. C They eliminate many animal species that exist at the time they occur. D They occur every 250 million years. 2. According to paragraph 2, scientists base their belief that a mass extinction is going on at present on which of the following? A The speed with which mass extinctions are happening today is similar to the speed of past extinctions. B The number of species that have died out since the last extinction event is extremely large. C Mass extinctions occur with regularity and it is time fo「a门othe「one. Cases in which many species become extinct within a geologically short interval of time are called mass extinctions. There was one such event at the end of the Cretaceous period (around 70 million years ago). There was another,
托福TPO35阅读Passage1原文文本+题目+答案解析
为了帮助大家高效备考托福，为大家带来托福TPO35阅读Passage1原文文本+题目+答案解析，希望对大家备考有所帮助。 Memphis:United Egypt's First Capital [1]The city of Memphis,located on the Nile near the modern city of Cairo,was founded around 3100 B.C.as the first capital of a recently united Egypt.The choice of Memphis by Egypt's first kings reflects the site's strategic importance.■First,and most obvious,the apex of the Nile River delta was a politically opportune location for the state's administrative center,standing between the united lands of Upper and Lower Egypt and offering ready access to both parts of the country.The older predynastic(pre-3100BC)centers of power,This and Hierakonpolis,were too remote from the vast expanse of the delta,which had been incorporated into the united state.■Only a city within easy reach of both the Nile valley to the south and the more spread out,difficult terrain to the north could provide the necessary political control that the rulers of early dynastic Egypt(roughly 3000-2600 B.C.)required.■ [2]The region of Memphis must have also served as an important node for transport and communications,even before the unification of Egypt.The region probably acted as a conduit for much,if not all,of the river-based trade between northern and southern Egypt.■Moreover,commodities(such as wine,precious oils,and metals)imported from the Near East by the royal courts of predynastic Upper Egypt would have been channeled through the Memphis region on their way south.In short,therefore,the site of Memphis offered the rulers of the Early Dynastic Period an ideal location for controlling internal trade within their realm,an essential requirement for a state-directed economy that depended on the movement of goods. [3]Equally important for the national administration was the ability to control communications within Egypt.The Nile provided the easiest and quickest artery of communication,and the national capital was,again,ideally located in this respect.Recent geological surveys of the Memphis region have revealed much about its topography in ancient times.It appears that the location of Memphis may have been even more advantageous for controlling trade,transport,and communications than was previously appreciated.Surveys and drill cores have shown that the level of the Nile floodplain has steadily risen over the last five millenniums.When the floodplain was much lower,as it would have been in predynastic and early dynastic times,the outwash fans(fan-shaped deposits of sediments)of various wadis(stream-beds or channels that carry water only during rainy periods)would have been much more prominent features on the east bank.The fan associated with the Wadi Hof extended a significant way into the Nile floodplain,forming a constriction in the vicinity of Memphis.The valley may have narrowed at this point to a mere three kilometers,making it the ideal place for controlling river traffic. [4]Furthermore,the Memphis region seems to have been favorably located for the
托福TPO阅读46文本+题目+答案
小编发布托福TPO46阅读本文+答案，希望帮助考生对照文本更好的研究真题，充分备考，争取理想成绩，实现留学梦想。 1. The Origins of Writing It was in Egypt and Mesopotamia (modern-day Iraq) that civilization arose, and it is there that we find the earliest examples of that key feature of civilization, writing. These examples, in the form of inscribed clay tablets that date to shortly before 3000 B.C.E., have been discovered among the archaeological remains of the Sumerians, a gifted people settled in southern Mesopotamia. The Egyptians were not far behind in developing writing, but we cannot follow the history of their writing in detail because they used a perishable writing material. In ancient times the banks of the Nile were lined with papyrus plants, and from the papyrus reeds the Egyptians made a form of paper; it was excellent in quality but, like any paper, fragile. Mesopotamia’s rivers boasted no such useful reeds, but its land did provide good clay, and as a consequence the clay tablet became the standard material. Though clumsy and bulky it has a virtue dear to archaeologists: it is durable. Fire, for example, which is death to papyrus paper or other writing materials such as leather and wood, simply bakes it hard, thereby making it even more durable. So when a conqueror set a Mesopotamian palace ablaze, he helped ensure the survival of any clay tablets in it. Clay, moreover, is cheap, and forming it into tablets is easy, factors that helped the clay tablet become the preferred writing material not only throughout Mesopotamia but far outside it as well, in Syria, Asia Minor, Persia, and even for a while in Crete and Greece. Excavators have unearthed clay tablets in all
托福TPO46阅读文本题附答案
托福TPO46阅读文本+题目+答案 1. The Origins of Writing It was in Egypt and Mesopotamia (modern-day Iraq) that civilization arose, and it is there that we find the earliest examples of that key feature of civilization, writing. These examples, in the form of inscribed clay tablets that date to shortly before 3000 B.C.E., have been discovered among the archaeological remains of the Sumerians, a gifted people settled in southern Mesopotamia. The Egyptians were not far behind in developing writing, but we cannot follow the history of their writing in detail because they used a perishable writing material. In ancient times the banks of the Nile were lined with papyrus plants, and from the papyrus reeds the Egyptians made a form of paper; it was excellent in quality but, like any paper, fragile. Mesopotamia’s rivers boasted no such useful reeds, but its land did provide good clay, and as a consequence the clay tablet became the standard material. Though clumsy and bulky it has a virtue dear to archaeologists: it is durable. Fire, for example, which is death to papyrus paper or other writing materials such as leather and wood, simply bakes it hard, thereby making it even more durable. So when a conqueror set a Mesopotamian palace ablaze, he helped ensure the survival of any clay tablets in it. Clay, moreover, is cheap, and forming it into tablets is easy, factors that helped the clay tablet become the preferred writing material not only throughout Mesopotamia but far outside it as well, in Syria, Asia Minor, Persia, and even for a while in Crete and Greece. Excavators have unearthed clay tablets in all these lands. In the Near East they remained in use for more than two and a half millennia, and in certain areas they lasted down to the beginning of the common era until finally yielding, once and for all, to more convenient alternatives. The Sumerians perfected a style of writing suited to clay. This script consists of simple shapes, basically just wedge shapes and lines that could easily be incised in soft clay with a reed or wooden stylus; scholars have dubbed it cuneiform from the wedge-shaped marks (cunei in Latin) that are its hallmark Although the ingredients are merely wedges and lines, there are hundreds of combinations of these basic forms that stand for different sounds or words. Learning these complex signs required long training and much practice; inevitably, literacy was largely limited to a small professional class, the scribes. The Akkadians conquered the Sumerians around the middle of the third millennium B.C.E., and they took over the various cuneiform signs used for writing Sumerian and gave them sound and word values that fit their own language. The Babylonians and Assyrians did the same, and so di d peoples in Syria and Asia Minor. ■ The literature of the Sumerians was treasured throughout the Near East, and long after Sumerian ceased to be spoken, the Babylonians and Assyrians and others kept it alive as a literary language, the way Europeans kept Latin alive after the fall of Rome. ■For the scribes of these non-Sumerian languages, training was doubly demanding since they had to know the values of the various cuneiform signs for Sumerian as well as for their own language. ■The contents of the earliest clay tablets are simple notations of numbers of commodities—animals, jars, baskets, etc. Writing, it would appear, started as a primitive form of bookkeeping. Its use soon widened to document the multitudinous
【威学教育】王鑫托福阅读TPO5-4阅读文本
【王鑫托福阅读】托福TPO6-1阅读文本 TPO6 TPO6-1 Powering the Industrial Revolution 1. 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. Running water was the best power source for factories since it could keep machines operating continuously, but since it was abundant only in Lancashire and Scotland, most mills and factories that were located elsewhere could not be water driven. B. The disadvantage of using waterpower is that streams do not necessarily flow in places that are the most suitable for factories, which explains why so many water-powered grain and textile mills were located in undesirable places. C. Since machines could be operated continuously only where running water was abundant, grain and textile mills, as well as other factories, tended to be located only in Lancashire and Scotland. D. Running water was the only source of power that was suitable for the continuous operation of machines, but to make use of it, factories had to be located where the water was, regardless of whether such locations made sense otherwise. In Britain one of the most dramatic changes of the Industrial Revolution was the harnessing of power. Until the reign of George 111(1760-1820), available sources of powe r for work and travel had not increased since the Middle Ages. There were three sources of power: animal or human muscles; the wind, operating on sail or windmill; and running water. Only the last of these was suited at all to the continuous operating of machines, and although
托福TPO13阅读Passage1原文文本+题目+答案解析
为了帮助大家高效备考托福，为大家带来托福TPO13阅读Passage1原文文本+题目+答案解析，希望对大家备考有所帮助。 ▉托福TPO13阅读Passage1原文文本： Types of Social Groups Life places us in a complex web of relationships with other people. Our humanness arises out of these relationships in the course of social interaction. Moreover, our humanness must be sustained through social interaction—and fairly constantly so. When an association continues long enough for two people to become linked together by a relatively stable set of expectations, it is called a relationship. People are bound within relationships by two types of bonds: expressive ties and instrumental ties. Expressive ties are social links formed when we emotionally invest ourselves in and commit ourselves to other people. Through association with people who are meaningful to us, we achieve a sense of security, love, acceptance, companionship, and personal worth. Instrumental ties are social links formed when we cooperate with other people to achieve some goal. Occasionally, this may mean working with instead of against competitors. More often, we simply cooperate with others to reach some end without endowing the relationship with any larger significance. Sociologists have built on the distinction between expressive and instrumental ties to distinguish between two types of groups: primary and secondary. A primary group involves two or more people who enjoy a direct, intimate, cohesive relationship with one another. Expressive ties predominate in primary groups; we view the people as ends in themselves and valuable in their own right. A secondary group entails two or more people who are involved in an impersonal relationship and have come together for a specific, practical purpose. Instrumental ties predominate in secondary groups; we perceive people as means to ends rather than as ends in their own right. Sometimes primary group relationships evolve out of secondary group relationships. This happens in many work settings. People on the job often develop close relationships with coworkers as they come to share gripes, jokes, gossip, and satisfactions. A number of conditions enhance the likelihood that primary groups will arise. First, group size is important. We find it difficult to get to know people personally when they are milling about and dispersed in large groups. In small groups we have a better chance to initiate contact and establish rapport with them. Second, face-to-face contact allows us to size up others. Seeing and talking with one another in close physical proximity makes possible a subtle exchange of ideas and feelings. And third, the probability that we will develop primary group bonds increases as we have frequent and continuous contact. Our ties with people often deepen as we interact with them across time and gradually evolve interlocking habits and interests.
【威学教育】王鑫托福阅读TPO21-1阅读文本
【王鑫托福阅读】托福TPO全集之TPO21-1 TPO21 TPO21-1 Geothermal Energy 'practical" in the passage is 1. According to the processes described in paragraph 1, what is the relationship between radioactivity and the steam produced by geothermal heat? A. Geothermally heated steam is produced when water is exposed to radioactivity deep underground. B. When water is introduced into holes drilled thousands of feet in the ground, it becomes radioactive and turns to steam. C. Radioactivity heats Earth's interior rock, which in turn can heat water to the point it becomes steam. D. When a reservoir of steam in subsurface rock is produced by radioactivity, it is said to be geothermally heated. 2. The word meaning to A. usable B. plentiful C. economical D. familiar Paragraph1: Earth's internal heat, fueled by radioactivity, provides the energy for plate tectonics and continental drift, mountain building, and
托福阅读模考软件TPO19文本解析(精)
智课网TOEFL备考资料 托福阅读模考软件TPO19文本+解析 摘要:小马托福资料下载栏目为大家提供最完整的TPO资料和TPO模考软件,其中本次分享的托福阅读模考软件TPO19文本+解析是TPO阅读中的一套,包含三篇文章每篇文章14道题目,形式与真实考试一样,考生们在练习的时候一定要将原文内容完全掌握然后再去作答。 阅读是托福考试最容易复习的一项了,但是大家还是不能轻易的放松,今天小编为大家带来的资料是托福阅读模考软件TPO19文本+解析,大家一起来看看本资料的精彩内容吧。 Succession, Climax, and Ecosystems In the late nineteenth century, ecology began to grow into an independent science from its roots in natural history and plant geography. The emphasis of this new "community ecology" was on the composition and structure of communities consisting of different species. In the early twentieth century, the American ecologist Frederic Clements pointed out that a succession of plant communities would develop after a disturbance such as a volcanic eruption, heavy flood, or forest fire. An abandoned field, for instance, will be invaded successively by herbaceous plants (plants with little or no woody tissue, shrubs, and trees, eventually becoming a forest. Light-loving species are always among the first invaders, while shade-tolerant species appear later in the succession. Clements and other early ecologists saw almost lawlike regularity in the order of succession, but that has not been substantiated. A general trend can be recognized, but the details are usually unpredictable. Succession is influenced by many factors: the nature of the soil, exposure to sun and wind, regularity of precipitation, chance colonizations, and many other random processes.