Passage 1 Attempts at Determining Earth's Age 文章阅读 第一步: 话题及中心思想 Passage 1 Attempts at Determining Earth's Age 本文属地理地质类话题。 文章话题是：尝试估计地球的年龄

文章阅读---第二步跳读，提炼文章中心思想 Paragraph 1 Since the dawn of civilization, people have been curious about the age of Earth. In addition, we have not been satisfied in being able to state merely the relative geologic age of a rock or fossil. Human curiosity demands that we know actual age in years. 第一段中心思想：人类渴望知道地球的年龄

文章阅读---第二步跳读，提炼文章中心思想 Paragraph 2 ①Geologists working during the nineteenth century understood that if they were to discover the actual age of Earth or of particular rock bodies, they would have to concentrate on natural processes that continue at a constant rate and that also leave some sort of tangible record in the rocks. （本段中心句：地质学家想知道地球的真正年龄，需要关注自然过程） ②Evolution is one such process, and geologist Charles Lyell (1797¨C1875) recognized this. （递进展开，指出自然过程：进化）③By comparing the amount of evolution exhibited by marine mollusks during the Tertiary Period with the amount that had occurred since then, Lyell estimated that 80 million years had elapsed since the beginning of the Tertiary Period. ④He came astonishingly close to the mark, since it was actually about 65 million years. （3和4句举例说明：Charles Lyell的研究方法及结果） ⑤However, for older sequences of evolutionary development, estimates based on rates of evolution were difficult, and not only because of missing parts in the fossil record. Rates of evolution for many orders of plants and animals were not well understood. （转折逻辑，阐述依赖进化来判定地球的年龄的不可靠性）

A. physical 有形的 B. related 相关的 C. significant 重要的 D. helpful 有帮助的 题型解答--词汇题 1.The word tangible in the passage is closest in meaning to A. physical 有形的 B. related 相关的 C. significant 重要的 D. helpful 有帮助的 Tangible 有形的，切实的， 所以答案选A

A. observations 观察 B. senses 感觉 C. series 序列 D. categories 分类 题型解答--词汇题 3. The word sequences in the passage is closest in meaning to A. observations 观察 B. senses 感觉 C. series 序列 D. categories 分类 Sequences 序列，顺序， 所以答案选C

题型解答—推断题 2. It can be inferred from paragraph 2 that Charles Lyell based his study of the marine mollusk fossils on which of the following assumptions A. The Tertiary Period was separated into divisions of time that were equal in length. B. Mollusks lived under rocks in the sea during the Tertiary period. C. Evolution of mollusks proceeded at a uniform rate over time. D. Mollusks have evolved less rapidly with the passing of time. 题干问到：Charles Lyell对marine mollusk的研究是基于以下哪个假设原文没有提到? 定位到第3句和第4句，通过第三纪期marine mollusk进化化石的研究，可以估计第三纪开始前已经过去8千万年了，但实际上纪录上只有6500万年，所以可以推断答案为C。

题型解答—推断题 3. According to paragraph 2, Lyell's strategy for estimating geologic dates was not very accurate for periods before the Tertiary Period partly because A. marine mollusks did not evolve until the Tertiary Period B. fossil records of the very distant past are incomplete C. there was not much agreement about how to identify or categorize earlier eras D. the duration of previous geologic periods was difficult to determine 根据题干定位到第5句“However, for older sequences of evolutionary development, estimates based on rates of evolution were difficult, and not only because of missing parts in the fossil record. Rates of evolution for many orders of plants and animals were not well understood.”可以得出答案为B

文章阅读---第二步跳读，提炼文章中心思想 Paragraph 3 ①In another attempt, geologists reasoned that if rates of deposition could be determined for sedimentary rocks, they might be able to estimate the time required for deposition of a given thickness of strata, or rock layers.（中心句：对sedimentary rocks的研究）②Similar reasoning suggested that one could estimate total elapsed geologic time by dividing the average thickness of sediment transported annually to the oceans into the total thickness of sedimentary rock that had ever been deposited in the past. （递进展开：指出研究结果）③Unfortunately, such estimates did not adequately account for past differences in rates of sedimentation or losses to the total section of strata during episodes of erosion. ④Also, some very ancient sediments were no longer recognizable, having been converted to igneous and metamorphic rocks in the course of mountain building. （3和4句递进展开：研究结果的不足）⑤Estimates of Earth's total age based on sedimentation rates ranged from as little as a million to over a billion years.（总结：得出结论）

题型解答—指代题 5.The phrase another attempt in the passage refers to A. trying to understand the fossil record B. trying to determine the evolutionary rate of marine mollusks C. trying to understand natural processes D. trying to determine Earth's actual age 第2段阐述了想要知道地球的年龄，需要关注自然过程，其中之一是：动物的进化，通过研究海洋软体动物的进化来估计地球的年龄；第3段后面介绍研究沉淀的岩石来估计地球的年龄，所以another attempt指的就是natural processes，故正确答案为D。

A. added 增加的 B. changed 变化的 C. restored 扭曲的 D reduced 减少的 题型解答--词汇题 6. The word converted in the passage is closest in meaning to A. added 增加的 B. changed 变化的 C. restored 扭曲的 D reduced 减少的 Converted 转变的，所以答案选B

题型解答—否定事实信息题 7. According to paragraph 3, all of the following were problems with the calculation of Earth's age using the study of sedimentary rocks EXCEPT A. the inconsistency of sedimentation rates over time B. the effect of geologic processes on sedimentary rock C. the expansion of some sedimentary rocks due to Earth's internal heat D. the loss of an unknown number of sedimentary layers due to erosion 根据题干定位到第3句和第4句“③Unfortunately, such estimates did not adequately account for past differences in rates of sedimentation or losses to the total section of strata during episodes of erosion. ④Also, some very ancient sediments were no longer recognizable, having been converted to igneous and metamorphic rocks in the course of mountain building.”可以得出答案为C。

文章阅读---第二步跳读，提炼文章中心思想 Paragraph 4-1 ①Yet another scheme for approximating Earth's age had been proposed in 1715 by Sir Edmund Halley (1656¨C1742), whose name we associate with the famous comet. （估计地球年龄的另一研究）②Halley surmised that the ocean formed soon after the origin of the planet and therefore would be only slightly younger than the age of the solid Earth. He reasoned that the original ocean was not salty and that subsequently salt derived from the weathering of rocks was brought to the sea by streams.（举例说明：阐述Halley 的研究及发现）Thus, if one knew the total amount of salt dissolved in the ocean and the amount added each year, it might be possible to calculate the ocean's age. （递进展开：研究的另一方向）In 1899, Irish geologist John Joly (1857¨C1933) attempted the calculation. From information provided by gauges placed at the mouths of streams, Joly was able to estimate the annual increment of salt to the oceans. Then, knowing the salinity of ocean water and the approximate volume of water, he calculated the amount of salt already held in solution in the oceans.（举例说明：John Joly的研究及结果）

文章阅读---第二步跳读，提炼文章中心思想 Paragraph 4-2 An estimate of the age of the ocean was obtained by dividing the total salt in the ocean by the rate of salt added each year. （递进展开：海水中每年增加的含盐率估计地球的年龄） Beginning with essentially nonsaline oceans, it would have taken about 90 million years for the oceans to reach their present salinity, according to Joly. The figure, however, was off the currently accepted mark of 4.54 billion by a factor of 50, largely because there was no way to account accurately for recycled salt and salt incorporated into clay minerals deposited on the sea floors.（ Joly的研究及结果）Even though in error, Joly's calculations clearly supported those geologists who insisted on an age for Earth far in excess of a few million years. The belief in Earth's immense antiquity was also supported by Darwin, Huxley, and other evolutionary biologists, who saw the need for time in the hundreds of millions of years to accomplish the organic evolution apparent in the fossil record.（（条件逻辑：Joly 的研究虽有缺陷，但被大多数地质学家接受）

A. thinking about 考虑 B. researching 研究 C. estimating 估计 题型解答--词汇题 8. The word approximating in the passage is closest in meaning to A. thinking about 考虑 B. researching 研究 C. estimating 估计 D. demonstrating 证明 approximating 大概，估计，所以答案选C

A. later 后来 B. furthermore 此外 C. evidently 显然地 D. accidentally 偶然地 题型解答--词汇题 9.The word subsequently in the passage is closest in meaning to A. later 后来 B. furthermore 此外 C. evidently 显然地 D. accidentally 偶然地 Subsequently 随后，所以答案选A

题型解答—否定事实信息题 10. According to paragraph 4, John Joly's calculations were founded on all of the following EXCEPT A. knowing how salty the ocean water is B. estimating how much salt enters the ocean each year C. accounting for the amount of salt that is recycled D. figuring the volume of water contained in the ocean 根据题干对应原文“From information provided by gauges placed at the mouths of streams, Joly was able to estimate the annual increment of salt to the oceans（对应B）. Then, knowing the salinity of ocean water (对应A) and the approximate volume of water （对应D）”所以答案选C

题型解答—事实信息题 11. According to paragraph 4, in which of the following ways could Joly's estimate of Earth's age be considered significant A. It proved that Halley's idea about the age of the ocean was fairly accurate. B. It indicated that Earth was much older than some scientists had claimed. C. It was favored by the majority of scientists at the end of the nineteenth century. D. It was the basis for much modern research into the salinity of the ocean. 根据题干定位原文最后几句“Even though in error, Joly's calculations clearly supported those geologists who insisted on an age for Earth far in excess of a few million years. The belief in Earth's immense antiquity was also supported by Darwin, Huxley, and other evolutionary biologists, who saw the need for time in the hundreds of millions of years to accomplish the organic evolution apparent in the fossil record.”说的是： Joly 的研究虽有缺陷，但被大多数地质学家接受，所以答案为C

题型解答—修辞目的题 12. The author mentions Darwin, Huxley, and other evolutionary biologists in order to A. provide evidence that Joly's calculations inspired scientists working on other lines of scientific inquiry B. support the claim that all of the leading scientists of the time believed that Earth was just over 90 million years old C. argue that Joly's calculations would have been more exact if he had collaborated with experts in other fields D. provide examples of scientists who believed the age of Earth to be greater than just a few million years, like Joly, in order to account for their findings 根据题干定位到“The belief in Earth's immense antiquity was also supported by Darwin, Huxley, and other evolutionary biologists, who saw the need for time in the hundreds of millions of years to accomplish the organic evolution apparent in the fossil record.” Joly 的研究虽有缺陷，但被大多数专家的支持，如Darwin, Huxley, and other evolutionary biologists，所以举例子来说明Joly 的研究价值，得到了其他专家的支持。所以答案选D.

题型解答—句子插入题 13. More fundamentally, Lyell's evolutionary approach is intrinsically limited because Earth existed long before life and evolution began. Evolution is one such process, and geologist Charles Lyell (1797¨C1875) recognized this. ■By comparing the amount of evolution exhibited by marine mollusks during the Tertiary Period with the amount that had occurred since then, Lyell estimated that 80 million years had elapsed since the beginning of the Tertiary Period. ■He came astonishingly close to the mark, since it was actually about 65 million years. ■However, for older sequences of evolutionary development, estimates based on rates of evolution were difficult, and not only because of missing parts in the fossil record. Rates of evolution for many orders of plants and animals were not well understood. 本段主要介绍Lyell的研究及结果，插入句说Lyell's evolutionary approach is intrinsically limited because..”说明是对研究结果的总结，所以放第4空比较合适。

题型解答—总结题 14. Drag your choices to the spaces where they belong. To review the passage, click on View Text. Answer Choices A. It was not until the nineteenth century that attempts were made to determine the relative geologic age of rocks and fossils.（内容错误，原文是对地球的年龄进行研究） B. In the nineteenth century, scientists made a number of important, but unsuccessful, attempts to calculate Earth's age from the record of various natural processes.（内容正确，对应原文第2段） C. Charles Lyell made a good estimate of the age of the Tertiary Period from the fossil record, but his method could not be extended to earlier geological periods. （内容错误，不是estimate of the age of the Tertiary Period from the fossil record） D. Darwin and Huxley supported the accuracy of John Joly's calculation of Earth's age because it agreed with their view of how long evolution had been in progress. （内容正确，对应原文第4段） E. Attempts were made to calculate Earth's age from the thickness of surviving sedimentary rock and from the current level of the oceans' salinity.（内容正确，对应原文第4段） F. Earth's true age, 4.54 billion years, was determined by combining data from the geological and fossil records.（内容错误，没有确定Earth's true age, 4.54 billion years） 所以正确答案为BDE。

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