小站论坛_托福论坛

[TPO阅读] TPO35托福阅读真题 Earth’s Age 阅读原文+题目免费查看

2868
0

Rank: 12Rank: 12

排名61

小站金币
5637
发表于 2017-5-19 16:59 |显示全部楼层
TPO模考软件是目前市面上唯一一款免费的托福备考工具,目前已更新到49套题(下载:TPO1-49免费下载)。为了让大家更好的使用TPO模考软件,这里小站教育编辑为大家整理了完整的TPO真题题目、文本以及答案解析,希望对大家的托福备考有帮助。
TPO35托福阅读答案解析>>>点击查看

Earth’s Age
One of the first recorded observers to surmise a long age for Earth was the Greek historian Herodotus, who lived from approximately 480 B.C. to 425 B.C. ■ He observed that the Nile River Delta was in fact a series of sediment deposits built up in successive floods. ■ By noting that individual floods deposit only thin layers of sediment, he was able to conclude that the Nile Delta had taken many thousands of years to build up. ■ More important than the amount of time Herodotus computed, which turns out to be trivial compared with the age of Earth, was the notion that one could estimate ages of geologic features by determining rates of the processes responsible for such features, and then assuming the rates to be roughly constant over time. ■ Similar applications of this concept were to be used again and again in later centuries to estimate the ages of rock formations and, in particular, of layers of sediment that had compacted and cemented to form sedimentary rocks.
It was not until the seventeenth century that attempts were made again to understand clues to Earth's history through the rock record Nicolaus Steno (1638-1686) was the first to work out principles of the progressive depositing of sediment in Tuscany However, James Hutton (1726-1797), known as the founder of modern geology, was the first to have the important insight that geologic processes are cyclic in nature. Forces associated with subterranean heat cause land to be uplifted into plateaus and mountain ranges. The effects of wind and water then break down the masses of uplifted rock, producing sediment that is transported by water downward to ultimately form layers in lakes, seashores, or even oceans. Over time, the layers become sedimentary rock. These rocks are then uplifted sometime in the future to form new mountain ranges, which exhibit the sedimentary layers (and the remains of life within those layers) of the earlier episodes of erosion and deposition.
Hutton's concept represented a remarkable insight because it unified many individual phenomena and observations into a conceptual picture of Earth’s history. With the further assumption that these geologic processes were generally no more or less vigorous than they are today, Hutton's examination of sedimentary layers led him to realize that Earth's history must be enormous, that geologic time is an abyss and human history a speck by comparison.
After Hutton, geologists tried to determine rates of sedimentation so as to estimate the age of Earth from the total length of the sedimentary, or stratigraphic, record. Typical numbers produced at the turn of the twentieth century were 100 million to 400 million years. These underestimated the actual age by factors of 10 to 50 because much of the sedimentary record is missing in various locations and because there is a long rock sequence that is older than half a billion years that is far less well defined in terms of fossils and less well preserved.
Various other techniques to estimate Earth's age fell short, and particularly noteworthy in this regard were flawed determinations of the Sun's age. It had been recognized by the German philosopher Immanuel Kant (1724-1804) that chemical reactions could not supply the tremendous amount of energy flowing from the Sun for more than about a millennium. Two physicists during the nineteenth century both came up with ages for the Sun based on the Sun's energy coming from gravitational contraction. Under the force of gravity, the compression resulting from a collapse of the object must release energy. Ages for Earth were derived that were in the tens of millions of years, much less than the geologic estimates of the lime.
It was the discovery of radioactivity at the end of the nineteenth century that opened the door to determining both the Sun’s energy source and the age of Earth. From the initial work came a suite of discoveries leading to radio isotopic dating, which quickly ted to the realization that Earth must be billions of years old, and to the discovery of nuclear fusion as an energy source capable of sustaining the Sun's luminosity for that amount of time. By the 1960s, both analysis of meteorites and refinements of solar evolution models converged on an age for the solar system, and hence for Earth, of 4 5 billion years.
1. The word "trivial" in the passage is closest in meaning to
O similar
O inaccurate
O small
O significant
Paragraph 1 is marked with ►
2. According to paragraph 1. Herodotus' observations of the Nile River Delta were significant because they allowed him to
O provide detailed records of the most significant floods in the history of the Nile
O develop a way of calculating the age of geologic features
O conclude that the Nile River Delta was as old as Earth
O predict when the river would flood and when it would not
Paragraph 1 is marked with ►
3. According to paragraph 2, James Hutton was the first person to
O understand clues to Earth's history through the rock record
O work out principles of the progressive depositing of sediment.
O realize that geologic processes happen in cycles.
O describe the forces associated with subterranean heat.
Paragraph 2 is marked with ►
4. The word "exhibit" in the passage is closest in meaning to
O replace
O show
O cover
O expand
Paragraph 2 is marked with
5. The word "episodes" in the passage is closest in meaning to
O occurrence
O locations
O effects
O combinations
Paragraph 2 is marked with ►
6. Which of the sentences below best expresses the essential information in the highlighted sentence m the passage? Incorrect choices change the meaning in important ways or leave out essential information.
O Hutton realized that if these geologic processes have always occurred at about the same rate as they do today. Earth's history is huge in comparison with human history.
O Hutton's examination of sedimentary layers led him to conclude that throughout Earth s long history, geologic processes have been generally the same as they are today.
O In spite of Hutton's contributions to the understanding of geologic processes, what is known about Earth's history is minor compared with what is known about human history.
O Hutton's examination of sedimentary layers was quite vigorous for his day, and his conclusions about geologic processes are among the most significant in human history.
Paragraph 3 is marked with ►
7. According to paragraph 4,what happened when geologists at the turn of the twentieth century tried to estimate Earth's age?
O They ignored Hutton's findings about rates of sedimentation and thus tended to underestimate the age by a factor of 10 to 50.
O Using the sedimentary record, they were able to guess the correct age within 100 million to 400 million years.
O They did not realize that much of the sedimentary record is missing and thus assumed that Earth is much younger than it actually is.
O They did not correctly calculate the rates of sedimentation and thus concluded that Earth is much older than it actually is.
Paragraph 4 is marked with ►
8. The word "flawed" in the passage is closest in meaning to
O several
O specific
O early
O incorrect
Paragraph 5 is marked with ►
9. Why is "gravitational contraction" mentioned in the passage?
O To show that questions about the Sun's energy source were as interesting to early scientists as questions about Earth's age.
O To provide evidence that Hutton's ideas led to advances in physics and astronomy as well as in geology.
O To explain why there is such a tremendous amount of energy flowing from the Sun.
O To cite a method for estimating the age of the Sun that was used to determine Earth s age.
Paragraph 5 is marked with ►
10. According to paragraph 5, Immanuel Kant recognized that the Sun's energy
O could not be sustained through chemical reactions over the long term.
O came from compression resulting from the force of gravity.
O was largely the result of chemical reactions that took place over a period of more than a millennium.
O was necessary to fuel most of the chemical reactions on Earth. Paragraph 5 is marked with ►
11. According to paragraph 6, which of the following is NOT true about scientists most recent estimate of Earth's age?
O It is based on information taken from the examination of meteorites.
O It is surprisingly consistent with estimates from the nineteenth century.
O It is confirmed by solar evolution models.
O It puts the age of Earth at about 4 5 billion years.
Paragraph 6 is marked with ►
12. Which of the following can be inferred from paragraph 6 about the formation of the solar system?
O The Sun was already billions of years old when the planets were formed. O The planets closest to the Sun formed first.
O Meteorites entered the solar system sometime after the planets were formed. O All parts of the solar system formed at approximately the same time.
Paragraph 6 is marked with ►
13. Look at the four squares [ ■ ]that indicate where the following sentence could be added to the passage.
This idea came to be known as the principle of uniformitarianism, and Herodotus was only the first to apply it
Where would the sentence best fit?
Click on a square [ ■ ] to insert the sentence in the passage.
One of the first recorded observers to surmise a long age for Earth was the Greek historian Herodotus, who lived from approximately 480 B.C. to 425 B.C. ■ He observed that the Nile River Delta was in fact a series of sediment deposits built up in successive floods. ■ By noting that individual floods deposit only thin layers of sediment, he was able to conclude that the Nile Delta had taken many thousands of years to build up. ■ More important than the amount of time Herodotus computed, which turns out to be trivial compared with the age of Earth, was the notion that one could estimate ages of geologic features by determining rates of the processes responsible for such features, and then assuming the rates to be roughly constant over time. ■ Similar applications of this concept were to be used again and again in later centuries to estimate the ages of rock formations and, in particular, of layers of sediment that had compacted and cemented to form sedimentary rocks.
14. Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting THREE answer choices that express the most important ideas in the passage. Some answer choices do not belong in summary because the express ideas that are not presented in the passage or are minor ideas in the passage. The Question is worth 2 points
Determining the age of Earth has been a difficult problem in the history of science.
Answers Choices
A. Herodotus attempted to calculate Earth's age by observing sediment deposits, but modem principles for estimating Earth's age from geologic processes arose from the work of Steno and Hutton.
B. Gaps in the sedimentary record began to be recognized by Kant and were later made clear by physicists studying the Sun's sources of energy.
C. Radio isotopic dating, made possible by the discovery of radioactivity, and the discovery of nuclear fusion cleared up questions about both Earth s age and the Sun's energy source.
D. Hutton described the effects of wind and water on masses of uplifted rock and was the first to suggest that much of the sedimentary record was missing due to erosion.
E. Early estimates of Earth's age based on the rates of geologic processes were inaccurate, and calculations based on estimates of the Sun's age and energy source were also extremely low.
F. In the 1960s scientists moved from analysis of meteorites to refinements of solar evolution models and determined the age of the solar system to be at least a billion years.
Drag your answer choices to the space where they belong. To remove an answer choice, double click on it.

回复

使用道具 举报

领取福利

我们将以您绑定的 (****)
作为接收批改短信的默认手机号码

订阅小站最新精品课程信息

领取福利

输入您的手机号码,批改动态随时掌握!

订阅小站最新精品课程信息

您可以在设置—密码安全—绑定手机中随时修改您的手机号码

领取福利

还差最后一步了!只要填写完邮箱即可同时获得批改短信提醒小站精品课程信息两大福利了!

领取福利

网站地图 | 最新帖子 | 联系我们 | 站点统计 | 版权声明 | 免责及隐私声明 © 2011-2018 ZHAN.com All Rights Reserved. 沪ICP备15003744号-3
  沪公网安备 31010602002658号

订阅最新机经

选择托福机经及考试日期进行预约,预约后机经将在考试前3-5天左右通过邮件和短信形式推送

热门机经*
考试日期*
立即订阅