托福(阅读)历年真题试卷汇编7(题后含答案及解析)

托福（阅读）历年真题试卷汇编7 (题后含答案及解析)

题型有： 3. Reading Comprehension

Sections Three：Reading Comprehension

Removing DamsP1: In the last century, many of the dams in the United States were built for water diversion, agriculture, factory watermills, and other purposes that allowed farming on lands that would otherwise be too dry, with low-cost hydroelectric power generation being a very significant side benefit. Building these dams was rather labor-intensive, which created jobs for workers and stimulated regional economic development. But those opposed to large dams can marshal a sobering array of criticisms based on those already built, which have provided some benefits but have without exception destroyed river environments and the human communities that depend on them.P2: Many, perhaps most, of the more than 90,000 dams in the country are now obsolete, expensive, and unsafe, and were built with no consideration of the environmental costs. As operating licenses come up for renewal in 1999, habitat restoration to original stream flows will be among the options considered. As these dams age and decay, they can also become public safety hazards, presenting a failure risk and a dangerous nuisance. Worse still, with the growth of the American population, more people are moving into risky areas. Dams that once could have failed without major repercussions are now upstream of cities and development. In 1998, the Army Corps announced that it would no longer be building large dams. In the few remaining sites where dams might be built, public opposition is so great that getting approval for projects is unlikely.P3: For many years, the United States Fish and Wildlife Service had advocated the removal of the Edwards Dam, which was built in 1837 on the Kennebec River in Augusta, Maine, to ease navigation and generate electricity. The Kennebec River was once home to all ten species of migratory fish native to Maine, along with several thriving commercial fisheries. Damming the river not only transformed the natural landscape, but it also prevented migration of salmon, shad, sturgeon, and other fish species up the river.In 1999, the Federal Energy Regulatory Commission (FERC) refused the renewal of the dam license due to excessive negative environmental impact, and the dam was removed, freeing a 17-mile stretch of the Kennebec River that had been submerged for 162 years. P4: The cost of keeping outdated hydroelectric equipment running decades after it was installed or upgrading dam safety systems may not be worth it. This was proven true on the Elwha River in the Olympic National Park in Washington when an extraordinarily rich salmon habitat was being disrupted by an outdated hydroelectric plant. Before dams were built on the Elwha River, 400,000 salmon returned each year to spawn, but that number dropped to fewer than 3,000 after dams were put up. Once the hydroelectric power generating capacities of the dams had outlived their useful lives, the importance of this salmon habitat necessitated the removal of the dams on the Elwha River. Simply removing the dams will not restore the salmon, however.

Where 50-kilogram king salmon once fought their way up waterfalls to lay their eggs in gravel beds, there are now only concrete walls holding back still water and deep beds of muddy deposits.P5: When the negative environmental effects outweigh the benefits, a dam may be considered for removal. The Hetch Hetchy Dam, whose construction was one of the first major defeats of the nascent American environmental movement, was approved in 1913 to assist earthquake-ravaged San Francisco. Environmentalists and nature lovers, who said the valley’s beauty surpassed even Yosemite Valley’s, have constantly fought for its removal. They claim that restoring Hetch Hetchy Valley could reclaim an area that is half the size of Yosemite Valley and nearly identical in terms of beauty. Revenue and increased local spending from tourism could offset some or all of the losses from removing the dam. This problem can be thought of as appraising the relative value of two scarce resources, water and space, in Yosemite National Park.P6: How does one weigh the many different economic, cultural, and aesthetic considerations for removing or not removing these dams? Do certain interests, such as the rights of native people or the continued existence of native species of fish or wildlife, take precedence over economic factors, or should this be a utilitarian calculation of the greatest good for the greatest number? And does that number include only humans, or do other species count as well?P4: ■ The cost of keeping outdated hydroelectric equipment running decades after it was installed or upgrading dam safety systems may not be worth it. ■ This was proven true on the Elwha River in the Olympic National Park in Washington when an extraordinarily rich salmon habitat was being disrupted by an outdated hydroelectric plant. ■ Before dams were built on the Elwha River, 400,000 salmon returned each year to spawn, but that number dropped to fewer than 3,000 after dams were put up. ■ Once the hydroelectric power generating capacities of the dams had outlived their useful lives, the importance of this salmon habitat necessitated the removal of the dams on the Elwha River. Simply removing the dams will not restore the salmon, however. Where 50-kilogram king salmon once fought their way up waterfalls to lay their eggs in gravel beds, there are now only concrete walls holding back still water and deep beds of muddy deposits.

1． According to paragraph 1, building dams was beneficial in each of the following ways EXCEPT

A．increasing the amount of land that could be used for farming B．strengthening local economies

C．increasing the availability of low-cost electricity D．expanding the aquatic habitats of native species

正确答案：D 解析：【否定事实信息题】末2行提到会破坏河流环境，与D选项矛盾。其他三个选项在原文中均可找到对应。

2． According to paragraph 2, the likelihood that new dams will be built has

decreased because

A．construction costs have increased enormously B．safety standards have become much higher

C．public opposition to dam construction has increased

D．at most suitable sites an existing dam would have to be removed first

正确答案：C 解析：【事实信息题】末句提到少数可能建大坝的地方的民众也非常反对，所以建造大坝的可能性变小了。

3． The word “obsolete’in the passage is closest in meaning to A．unpopular B．inefficient C．out of date D．unnecessary

正确答案：C 解析：【词汇题】obsolete意为“过时的”，后文有age和decay这样的呼应。

4． Paragraph 2 supports which of the following ideas about operating licenses for large dams?

A．Since 1999 licenses have been renewed only for small dams.

B．Before 1999, owners applying for a license renewal were more likely to have their applications than they were after that date.

C．Strong public opposition to their renewal was common even before 1999, but it was based on safety considerations, not on environmental ones.

D．The environmental cost of dams has been a minor consideration in license renewal applications since 1999.

正确答案：B 解析：【推断题】第2句说到随着运营许可证的更新，水源地的生态恢复被纳入条款，而1999年之前的大坝建造没有考虑到环境的问题，所以1999年之前申请运营许可证更容易一些。

5． According to paragraph 3, why did the United States Fish and Wildlife Service want the Edwards Dam removed?

A．Because the age of the dam made it unsafe.

B．Because the dam was negatively affecting various species of fish. C．Because the dam had caused wetlands to form.

D．Because the dam no longer provided economic benefits.

正确答案：B 解析：【事实信息题】本页最后一句提到很多年来，美国鱼类及野生动物管理局一直提出要拆除这个大坝。因为它阻碍了很多鱼类的迁徙。

6． Paragraph 3 suggests that one main consideration for keeping the Edwards Dam was

A．the electricity it generated.

B．the length of time it had been in operation, C．the high cost of removing it.

D．the fact that removing it would set a bad example.

正确答案：A 解析：【事实信息题】首句末行提到当初建造大坝是为了便利航行与发电，所以要保留大坝的理由是它能发电这个好处。

7． According to paragraph 4, why would removing the Elwha and Glines dams not be enough to restore salmon to the Elwha River?

A．They are not the only dams on the Elwha River.

B．The number of salmon is too small for the fish to recover.

C．Too many species of salmon are competing for survival in one river. D．The dams have left the river’s spawning beds in an unusable condition.

正确答案：D 解析：【推断题】末2行提到鲑鱼游到上游的瀑布，在砾石层产卵，但是现在只有水泥墙挡着静止的水以及厚厚的淤泥层，所以只移除大坝是不够的，因为它使得鲑鱼失去了产卵地。

8． The word “disrupted” in the passage is closest in meaning to A．modified B．affected C．upset

D．discharged

正确答案：C 解析：【词汇题】disrupted意为“扰乱”。

9． The word “offset” in the passage is closest in meaning to A．counteract B．embark on C．exceed D．challenge

正确答案：A 解析：【词汇题】offset意为“抵消”。

10． According to paragraph 5, why do environmental groups want the Hetch Hetchy Dam removed?

A．To assist earthquake-ravaged San Francisco. B．To compete with Yosemite Valley

C．To increase the size of Yosemite National Park D．To restore a valley to its original beauty

正确答案：D 解析：【推断题】第3句说环境保护主义机构认为赫奇峡谷恢复后可以增加大约有优胜美地峡谷一半的规模，而且可以恢复得与它一样美丽。所以环境保护机构想拆掉赫奇大坝是为了恢复该峡谷原本的美景。

11． The phrase “take precedence over” in the passage is closest in meaning to A．affect

B．have greater importance than C．get included among D．minimize

正确答案：B 解析：【词汇题】take precederice over意为“优先于，比……重要”。

12． What is the role of paragraph 6 in the passage?

A．To propose a method for deciding whether a given dam should be removed B．To emphasize the complexity of the issues involved in deciding what should be done about dams

C．To suggest that the recent tendency not to build new dams may be wrong D．To sum up the points made earlier in the passage about the advantages and disadvantages of removing dams

正确答案：B 解析：【修辞目的题】第六段第一句提问应该如何去从经济、文化和美观等各种不同的角度去衡量是否要拆除这些大坝，以反问的方式来强调拆不拆除大坝是一件非常复杂的事情。涉及多个影响因素。

13． Look at the four squares [■] that indicate where the following sentence could be added to the passage.Economic reasons often provide a convincing reason to remove a dam.Where would the sentence best fit?Click on a square [■] to add the sentence to the passage.

正确答案：A 解析：【句子插入题】插入句中提到经济因素，原文中只有A空后提到cost问题，前后形成内容上的连贯。

14． An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some answer choices do not belong in the

summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points. Drag your choices to the spaces where they belong. To review the passage, click on View Text.Many dams were built in the United States during the last century, and they provided a broad range of economic benefits.---Answer ChoicesA Until recently, the emphasis in dam building was on the economic benefits of low-cost energy and water that dams provided, but more attention is now being paid to the damage they cause. B Environmental groups now have a very good chance of forcing the removal of two major dams, the dam on the Elnha River and the Hetch Hetchy Dam in the valley. C The removal of dams remains controversial because of complex factors that are involved in weighing their advantages and disadvantages. D Since the late 1990s, dams constructed without considerations for environment costs, especially those negatively impact human and aquatic creatures, have been considered to remove. E Until recently, the main reason for removing dams was to restore salmon runs, but it is now recognized that a more important reason to remove dams is that they are no longer safe. F Although the U. S. government originally planned to remove the Elwha and Glines Dams in Washington, the enormous expense of removal has resulted in a postponement of this effort.

正确答案：A，C，D 解析：【文章总结题】本文主要讲了20世纪美国的大坝，大坝具有提供低成本的水、电，促进经济发展等优点，但是建造大坝带来的问题也很严重；20世纪90年代末，一些危害性很大的水坝被建议拆除：但是是否拆除一个大坝是非常复杂的事，因为涉及多个影响因素。因此涉及美国大坝优缺点及是否拆除问题的A、C、D选项正确。B、E、F三个选项属于细节偏离主旨，或者与文章内容不一致。

Sumerian ContributionsP1: Before about 4500 B.C., lower Mesopotamia, the whole plain between and on either side of the Tigris and Euphrates rivers, was much less densely populated than other inhabited regions of the Near and Middle East. Each year the two great rivers were swollen with the winter snows of the northern mountains, and each year at flood stage they spread a thick layer of immensely fertile silt across the flood plain where they approached the Persian Gulf. But without domestic animals and beasts, this swampy delta was not suited to the primitive hoe-centric tilling culture of early agriculture. Besides, the Tigris-Euphrates plain lacked minerals and trees. However, it was in this unpromising area, between 3500 and 3000 B. C, that agricultural settlers created a wealth of city-states that constituted Sumer, of which the best known is Ur. The Sumerians appeared at the dawn of history as a fully developed society with a technology and organization that was distinct from and superior to other societies of the time. Even civilization itself seems to have stemmed from this alien and mysterious people.P2: This delta, a land of swamps rich in fish, wildlife, and date palms, was the most challenging and rewarding of the three natural units into which the river valleys were divided. Reasons for their being challenging lie in that the rivers not only sustained life, but they also destroyed it with frequent floods that ravaged entire cities. Although land nearer to the rivers was fertile

and good for crops, portions of land farther from the water were dry and largely uninhabitable. Therefore, the development of drainage and irrigation systems was essential for Sumerians to harness the full productivity of this land,which in turn required a large and well-disciplined workforce, as well as skilled management and supervision—the latter were supplied by a class of priests and warriors who ruled a large population of peasants and artisans.P3: The economy that sustained the people of Sumer relied on agriculture and trade. To support agriculture, Sumerians created sophisticated water transport systems that would both irrigate crops during dry periods and control flooding during the spring. This water management enabled them to build up a food surplus for trading. They exchanged barley and wheat to supplement a scarcity of stone and lumber, as well as copper and bronze, thereby contributing to the diffusion of Sumerian civilization. In Sumerian cities, stone imported by sea through the Persian Gulf from Oman and downriver from the mountains of Anatolia and the Caucasus had to complete with imported copper, and the latter proved more economical and effective for a variety of uses. Sumerians would have plowed with stone and cut with clay sickles, and went on to using metal plows with the development of metal-working skills.P4: One of the greatest accomplishments of the Sumerian people was the invention of a writing system, likely growing out of commercial record keeping. Each Sumerian city rose up around the shrine of a local god. As a reflection of a city’s wealth, its temple became an elaborate structure. Both economic and religious organizations centered on the temple of the local patron deity, represented by a priestly hierarchy, in which a corporation run by priests became the greatest landowners among the Sumerians. Common Sumerians remained illiterate and without power, while kings, once elected by common people, became monarchs. Common people were obliged to pay taxes to the government in the form of a percentage of their crops, which the city could either sell or use to feed its soldiers and others it supported. In order to keep records of the sources and uses of this tribute, simple pictographs on clay tablets appeared sometime before 3000 B.C. By about 2800 B.C., the pictographs had been stylized into the system of writing known as cuneiform, a distinctive characteristic of Mesopotamian civilization. It is one of the few examples in history of a significant innovation from a bureaucratic organization.P5: Whether the Sumerians were the first to develop writing is uncertain, but theirs is the oldest known system of writing. The clay tablets on which they wrote were very durable when baked. Archaeologists have dug up many thousands of them—some dated earlier than 3000 B.C. The cuneiform texts recorded messages and historical events as well as commercial transactions. They evolved into producing written sagas such as the Epic of Gilgamesh, the world’s oldest surviving literary work.P4: One of the greatest accomplishments of the Sumerian people was the invention of a writing system, likely growing out of commercial record keeping. Each Sumerian city rose up around the shrine of a local god. As a reflection of a city’s wealth, its temple became an elaborate structure. ■ Both economic and religious organizations centered on the temple of the local patron deity, represented by a priestly hierarchy, in which a corporation run by priests became the greatest landowners among the Sumerians. ■ Common Sumerians remained illiterate and

without power, while kings, once elected by common people, became monarchs. ■ Common people were obliged to pay taxes to the government in the form of a percentage of their crops, which the city could either sell or use to feed its soldiers and others it supported. ■ In order to keep records of the sources and uses of this tribute, simple pictographs on clay tablets appeared sometime before 3000 B.C. By about 2800 B.C., the pictographs had been stylized into the system of writing known as cuneiform, a distinctive characteristic of Mesopotamian civilization. It is one of the few examples in history of a significant innovation from a bureaucratic organization.

15． The word “unpromising” in the passage is closest in meaning to A．unfavorable B．underdeveloped C．distant D．expansive

正确答案：A 解析：【词汇题】unpromising意为“没有前途的”。

16． The phrase “a wealth of” in the passage is closest in meaning to A．a strong competition among B．a valuable source of C．a deep respect for D．an abundance of

正确答案：D 解析：【词汇题】a wealth of意为“大量的”。

17． According to paragraph 1, which of the following was NOT true of lower Mesopotamia before 4500 B.C.?

A．It was flooded every year by rivers.

B．Its soil was unsuitable for early hoe culture agriculture. C．It was comparatively dense in population. D．It had few trees.

正确答案：C 解析：【否定事实信息题】文中提到了美索不达米亚平原下游地区一年一度的洪水、不适合早期的锄耕农业、缺少树木、并且首句提到这个地区人口密度并不高。

18． According to paragraph 2, which of the following was true of the soil in lower Mesopotamia?

A．It was relatively unfertile until humans added other, richer types of soil to it. B．It reached full productivity only when elaborate drainage and irrigation

systems were added.

C．Its most valuable nutrients were washed away by the spring floods of the Tigris and Euphrates rivers.

D．Its silt was removed by a large, well-disciplined workforce.

正确答案：B 解析：【事实信息题】末句提到如果苏美尔人想要让这块土地物尽其用的话，发展排水以及灌溉系统是非常重要的。

19． According to paragraph 2, which of the following was true of priests and warriors in Sumerian society?

A．Their technical expertise was essential in the development of new irrigation and drainage systems.

B．They encouraged peasants and artisans to perfect the refinements of civilization.

C．They were responsible for managing and supervising the workforce. D．They alone paid the taxes that funded the construction of temples.

正确答案：C 解析：【事实信息题】破折号后提到发展排水以及灌溉系统需要大量训练有素的劳力和熟练的管理与监督，而后者是由统治着大量农民和工匠的祭司与战士来完成的。

20． The phrase “scarcity of in the passage is closest in meaning to A．using up B．looking for C．lacking in

D．uninterested in

正确答案：C 解析：【词汇题】scarcity of意为“稀少”。

21． The word “diffusion” in the passage is closest in meaning to A．stability B．spread C．prosperity D．productivity

正确答案：B 解析：【词汇题】diffusion意为“传播”。

22． Which of the following is mentioned in paragraph 3 as an effect of Sumerian trade?

A．The spread of Sumerian civilization to people outside Sumer

B．The discovery of copper

C．A rise in the price of textiles, pottery, and other goods sold within Sumer D．An increase in the scarcity of stone within Sumer

正确答案：A 解析：【事实信息题】文中提到苏美尔人用大麦和小麦交换稀少的石头、木材以及铜和青铜，也因此传播了苏美尔文明。

23． 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．Sumeriancities developed a trade in copper and stone that extended as far as Oman in the Persian Gulf and the mountains of Anatolia and the Caucasus.

B．Sumerian cities competed with traders elsewhere to produce copper that was more economical and useful than stone.

C．In Sumerian cities, imported copper often proved more economical and useful than imported stone.

D．The copper and stone imported from Oman, Anatolia, and the Caucasus proved more economical and effective than the copper and stone found in Sumerian cities.

正确答案：C 解析：【句子简化题】原文是一个比较句，句子主干为“stone …had to compete with…copper”，C选项表达了这种比较的含义。

24． In paragraph 4, why does the author point out that the economic and religious organizations of early Sumerian cities centered on local temples?

A．To identify the bureaucratic needs that led to the development of writing B．To identify factors responsible for the significant influence of Sumerian writing on subsequent civilizations

C．To explain why few examples of significant innovations have issued from a bureaucratic organization

D．To explain why the use of simple pictographs eventually became stylized into the system of writing known as cuneiform

正确答案：A 解析：【修辞目的题】文中提到经济与宗教组织都以当地守护神的寺庙为中心衍生出一个祭司阶级，普通平民选出国王，就有义务向政府上交一定比例的粮食。为了记录这些贡品的来源及去处，就开始有了简单的象形文字，后来发展成了楔形文字。作者提这个点是为了说明官僚的需求最终导致了文字的产生。

25． Paragraph 4 implies all the following about cuneiform EXCEPT: A．It arose after 3000 B.C.

B．It involved stylized pictographs.

C．It was designed to further the purposes of the priestly bureaucracy. D．It was developed outside of the early temple cities.

正确答案：D 解析：【否定事实信息题】文中提到楔形字大约在公元前2800年出现、有成形的象形字、是为了官僚主义发展出的文字。

26． According to paragraph 5, which of the following was true of Sumerian writing ?

A．Knowledge of it was limited to the temple-centered administration. B．It was used for purposes beyond those for which it was first created. C．It was used primarily to help keep the traditional leadership in power. D．It led to further technological developments by 2800 B.C.

正确答案：B 解析：【事实信息题】末句提到楔形文字被用来记载消息以及历史事件，甚至发展出文学，这些都超出了它原本的目的。

27． Look at the four squares [■] that indicate where the following sentence could be added to the passage.They were viewed as agents of and responsible to the gods.Where would the sentence best fit?Click on a square [■] to add the sentence to the passage.

正确答案：C 解析：【句子插入题】空前提到苏美尔人选出国王作为最高统治者，插入句进一步补充说明他们被认为是神派来的并且对神负责。空后顺理成章指出人民有义务交税。通过They的指代去解题。

28． An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some answer choices do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points. Drag your choices to the spaces where they belong. To review the passage, click on View Text.Sumer in Mesopotamia created civilizaiton that is more advanced than that of other regoins---Answer ChoicesA Utilizing the full productive power of the annual flood of the Tigris and Euphrates rivers required an elaborate system of drainage and irrigation. B In spring and early summer, snowmelt from the northern mountains caused massive flooding in the lower reaches of the rivers, destroying both crops and settlements. C Since Sumer was virtually devoid of natural resources other than its rich soil, it traded with other people, causing the spread of Sumerian civilization. D Archaeologists have dug up many thousands of long-lasting clay tablets, which dated earlier than 3000 B.C. E Immediately to the north of Sumer, where the two rivers came most closely together, the plain was less subject to flooding but made fertile by rainfall and irrigation. F

Sumer’s greatest contribution to subsequent civilizations, the invention of writing, is a result of economy, and was used for various purposes later.

正确答案：A，C，F 解析：【文章总结题】本文主要讲述苏美尔文明的发展以及他们的贡献。苏美尔地区受到洪水的影响，有着肥沃的土壤，但同时也要承担被摧毁的风险，所以必须要有完善的排水和灌溉系统才能充分利用洪水；苏美尔地区的两大经济来源是农业和贸易。他们用剩余的农产品跟别人交易，同时也促进了他们自己文明的传播；苏美尔人最大的贡献是发明了文字。而后来文字也被用在不同的领域。因此涉及苏美尔文明发展的A、C、F选项正确。B、D选项属于细节偏离主旨，E在文章中未提及。

Surface Fluids on Venus and EarthP1: When astronomers first pointed their rudimentary telescopes at Venus, they saw a world shrouded in clouds. Here on Earth, clouds mean water, so early astronomers imagined a tropical world with constant rainfall. The truth, of course, is that the hydrological state on Venus is quite different from that of Earth. The hydrologic cycle describes the continuous movement of liquid above, on, and below the surface of a planet. These movements derive their energy from the Sun and the gravitational forces of the planet itself, and in turn redistribute energy around the globe through atmospheric circulation. As fluids interact with surface materials, water molecules move particles repeatedly through solid, liquid, and gaseous phases or react chemically with them to modify and produce materials. On a solid planet with a hydrosphere and an atmosphere, only a tiny fraction of the planetary mass flows as surface fluids. Yet, the movements of these fluids can drastically alter a planet.P2: Imagine Venus a long time ago. The planet is nearly identical to the Earth in size, mass, composition and distance from the Sun. However, it lacks any sign of a hydrologic system—there are no streams, lakes, oceans, or glaciers. It begins like the Earth with global oceans, carbon dioxide dissolved in the oceans, and carbonate rocks forming at the bottoms of the oceans. But because Venus is just a tiny bit smaller than the Earth, it has less radioactive heat sources inside. Thus, at some time in the distant past, perhaps only 500 million to 1 billion years ago, Venus may have run out of enough internal heat to continue to drive the tectonic activity. Alternatively, because Venus is a little closer to the Sun, we would expect that the original temperature of Venus should have been a little warmer than that of the early Earth. The slightly elevated temperature puts a bit more water in the oceans and atmosphere and a bit less in the rocks. This makes the rocks harder since water serves as a lubricant for the plate tectonic process. Either way, tectonic activity begins to slow down. Because Venus receives more heat from the Sun, water released from the interior evaporated and rose to the upper atmosphere, where the Sun’s ultraviolet rays broke the molecules apart. Much of the freed hydrogen escaped into space, and Venus lost its water. Without water, Venus became less and less like Earth and kept an atmosphere filled with carbon dioxide. On Earth, liquid water removes carbon dioxide from the atmosphere and combines it with calcium, through rock weathering, to form carbonate sedimentary rocks. Without liquid water to remove carbon from the

atmosphere, prohibiting the formation of carbonate minerals, the level of carbon dioxide in the atmosphere of Venus remains high.P3: Like Venus, Earth is large enough to be geologically active and for its gravitational field to hold an atmosphere. But fortunately, being further away, it has less heating from the sun and allows water to exist as a liquid, a solid, and a gas. Water is thus extremely mobile and moves rapidly over the planet in a continuous hydrologic cycle. Driven by energy from the sun, water is constantly being cycled from the ocean, through the atmosphere, and ultimately back to the oceans. As a result, Earth’s surface has been continually changed and eroded into delicate systems of river valleys—a remarkable contrast to the surfaces of other planetary bodies where impact craters dominate. Other geologic changes occur when the gases in the atmosphere or water react with rocks at the surface to form new chemical components with different properties. Weathering breaks down rocks into gravel, sand, and sediment, and is an important source of key nutrients such as calcium and sulfur. Estimates indicate that, on average, Earth’s surface weathers at a rate of about 0.5 millimeter per year. Actual rates may be much higher at specific locations and may have been accelerated by human activities. However, none of these would have happened if our planet had spun a little further from or nearer to the sun. Because liquid water was present, self-replicating molecules of carbon, hydrogen, and oxygen developed life early in Earth’s history and have rapidly modified its surface, blanketing huge parts of the continents with greenery.P2: Imagine Venus a long time ago. The planet is nearly identical to the Earth in size, mass, composition and distance from the Sun. ■ However, it lacks any sign of a hydrologic system—there are no streams, lakes, oceans, or glaciers.■ It begins like the Earth with global oceans, carbon dioxide dissolved in the oceans, and carbonate rocks forming at the bottoms of the oceans. ■But because Venus is just a tiny bit smaller than the Earth, it has less radioactive heat sources inside. Thus, at some time in the distant past, perhaps only 500 million to 1 billion years ago, Venus may have run out of enough internal heat to continue to drive the tectonic activity. Alternatively, because Venus is a little closer to the Sun, we would expect that the original temperature of Venus should have been a little warmer than that of the early Earth. The slightly elevated temperature puts a bit more water in the oceans and atmosphere and a bit less in the rocks. This makes the rocks harder since water serves as a lubricant for the plate tectonic process. Either way, tectonic activity begins to slow down. Because Venus receives more heat from the Sun, water released from the interior evaporated and rose to the upper atmosphere, where the Sun’s ultraviolet rays broke the molecules apart. ■ Much of the freed hydrogen escaped into space, and Venus lost its water. Without water, Venus became less and less like Earth and kept an atmosphere filled with carbon dioxide. On Earth, liquid water removes carbon dioxide from the atmosphere and combines it with calcium, through rock weathering, to form carbonate sedimentary rocks. Without liquid water to remove carbon from the atmosphere, prohibiting the formation of carbonate minerals, the level of carbon dioxide in the atmosphere of Venus remains high.

29． The word “modify” in the passage is closest in meaning to A．obtain B．change C．replace D．absorb

正确答案：B 解析：【词汇题】modify意为“修改”。

30． The word “drastically” in the passage is closest in meaning to A．gradually B．permanently C．extensively D．possibly

正确答案：C 解析：【词汇题】drastically意为“剧烈地”。

31． Paragraph 1 supports all of the following statements about fluids EXCEPT: A．They can chemically react with particles on a planet’s surface. B．Most of their mass does not flow but remains in place.

C．Their movements can reshape the surface of certain kinds of planets. D．Their movements is driven by the Sun and by gravity.

正确答案：B 解析：【否定事实信息题】A，C，D都可以在文中找到明显都对应，选项B文中未提及。

32． The word “prohibiting” in the passage is closest in meaning to A．preventing B．speeding up C．affecting D．encouraging

正确答案：A 解析：【词汇题】prohibiting意为“阻止”。 33． According to paragraph 2, what is one difference between Earth and Venus? A．Earth has less water in its atmosphere than Venus does. B．Earth has a hydrologic system, but Venus does not. C．Earth is less geologically active than Venus is. D．Earth has more carbon dioxide than Venus does.

正确答案：B

解析：【事实信息题】第3句提到金星上缺乏水系统。因此答案为B。

34． It can be inferred from paragraph 2 that Earth evolved differently than Venus did in part because

A．there was more volcanic activity on early Venus than on early Earth B．they received different amounts of solar energy C．their interiors contained different amounts of heat

D．their early atmosphere contained different levels of oxygen and nitrogen

正确答案：B 解析：【推断题】文中提到了两个原因：一是体积小，内部热量少；二是距离太阳更近，吸收的热量多。选项中涉及第二个原因，答案为B。注意C为非推断内容。

35． According to paragraph 2, all of the following played a role in keeping carbon dioxide levels high in the atmosphere of Venus EXCEPT

A．the breaking apart of water molecules by ultraviolet rays B．the evaporation of water released from the planet’s interior C．the escape of hydrogen into space

D．the release of molecules from melting metals such as lead

正确答案：D 解析：【否定事实信息题】A、B、C都可以在倒数第5句中找到明显都对应，选项D文中未提及。

36． The word “ultimately” in the passage is closest in meaning to A．finally B．slowly C．repeatedly D．constantly

正确答案：A 解析：【词汇题】ultimately意为“最后”。

37． According to paragraph 3, Earth’s surface is different from the surfaces of many other planetary bodies in which of the following ways?

A．It is more strongly marked by river valleys and erosion. B．It is more geologically active. C．It is covered by impact craters. D．It has an atmosphere.

正确答案：A 解析：【事实信息题】破折号后提到“remarkable contrast to the surfaces of other planetary bodies where impact craters dominate”说明此处谈到了与其他星球的差

异，破折号解释说明的正是前面的“river valleys”，因此答案为A。

38． According to paragraph 3, why is water able to move so freely on Earth? A．Earth’s temperatures are such that water exists in solid, liquid, and gas forms. B．Earth is large enough to be geologically active and for its gravitational field to hold an atmosphere.

C．Earth’s surface allows river valleys to develop across the landscape.

D．Earth has active winds that blow across seas and oceans, causing fluid movements.

正确答案：A 解析：【推断题】第3句提到“Water is thus extremely mobile and moves rapidly over the planet”，此句是结果，说明第2句是原因，答案为A。

39． Why does the author point out that on Earth “gases in the atmosphere or water react with rocks at the surface to form new chemical components”?

A．To explain why scientists believe that few areas on Earth have been untouched by flowing water

B．To identify one of several ways in which the movement of fluids can affect the surface of a planet

C．To provide evidence that fluid movements are caused by gravity flow systems energized by the Sun

D．To identify an effect of wind scouring fine particles away from large areas

正确答案：B 解析：【修辞目的题】当提问内容出现时会产生其他地质变化，说明提问内容是变化的原因之一，答案为B。

40． 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．Life on Earth is responsible for many changes to the planet’s surface, including blankets of greenery.

B．Self-replicating molecules of carbon, hydrogen, and oxygen led to the development of life early in Earth’s history.

C．The presence of water made it possible for life to develop early in Earth’s history and to significantly change its surface.

D．Early in life’s history on Earth, self-replicating molecules of carbon, hydrogen, and oxygen began blanketing the surface in greenery.

正确答案：C 解析：【句子简化题】文中句子提到了一对因果关系，并且结果包括两个——产生生命和改变地表形态，满足文中逻辑同时包括了所有信息的是答案C。

41． Look at the four squares [■] that indicate where the following sentence could be added to the passage.Venus may not have always been this way.Where would the sentence best fit?Click on a square [■] to add the sentence to the passage.

正确答案：B 解析：【句子插入题】插入文本提到金星并不总是这样，说明此句前后谈到的情形不同。B处前提到金星上没有水文系统，后面说开始的时候有海洋，所以答案是B。

42． An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some answer choices do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points. Drag your choices to the spaces where they belong. To review the passage, click on View Text.Over time, the movement of surface fluids has greatly changed Venus and Earth.---Answer ChoicesA Although Venus is about the same size as Earth, its greater volcanic activity has added considerably to carbon dioxide levels in its atmosphere. B Like Venus, Earth has an atmosphere, but Earth’s atmosphere has far more oxygen and nitrogen than does the atmosphere of Venus. C On Earth, chemical reactions involving fluids remove carbon dioxide from the atmosphere by giving rise to carbonate rocks, and winds energized by gravity flow systems move fine particles from one place to another. D Because Venus lost the water it originally had, most of its carbon dioxide remained in its atmosphere, causing the planet to become very warm. E On Earth, the dominance of river valley landscapes and the existence of life are due to the planet’s hydrologic cycle. F The evaporation of liquid water from Earth’s surface is largely limited by the life forms that have developed, particularly the vegetation.

正确答案：C，D，E 解析：【文章总结题】本文讨论了金星和地球上水存在或消失的原因。因此涉及影响因素的C、D、E选项正确。A、B、F文中未提及。