TOEFL阅读真题精选.docx
《TOEFL阅读真题精选.docx》由会员分享,可在线阅读,更多相关《TOEFL阅读真题精选.docx(18页珍藏版)》请在淘文阁 - 分享文档赚钱的网站上搜索。
1、TOEFL阅读真题精选托福阅读真题1 There are only a few clues in the rock record about climate in the Proterozoic eon. Much of our information about climate in the more recent periods of geologic history comes from the fossil record, because we have a reasonably good understanding of the types of environment in whi
2、ch many fossil organisms flourished. The scarce fossils of the Proterozoic, mostly single-celled bacteria, provide little evidence in this regard. However, the rocks themselves do include the earliest evidence for glaciation, probably a global ice age. The inference that some types of sedimentary ro
3、cks are the result of glacial activity is based on the principle of uniformitarianism, which posits that natural processes now at work on and within the Earth operated in the same manner in the distant past. The deposits associated with present-day glaciers have been well studied, and some of their
4、characteristics are quite distinctive. In 2.3-billion-year-old rocks in Canada near Lake Huron (dating from the early part of the Proterozoic age), there are thin laminae of fine-grained sediments that resemble varves, the annual layers of sediment deposited in glacial lakes. Typically, present-day
5、varves show two-layered annual cycle, one layer corresponding to the rapid ice melting and sediment transport of the summer season, and the other, finer-grained, layer corresponding to slower winter deposition. Although it is not easy to discern such details in the Proterozoic examples, they are alm
6、ost certainly glacial varves. These fine-grained, layered sediments even contain occasional large pebbles or dropstones, a characteristic feature of glacial environments where coarse material is sometimes carried on floating ice and dropped far from its source, into otherwise very fine grained sedim
7、ent. Glacial sediments of about the same age as those in Canada have been found in other parts of North America and in Africa, India, and Europe. This indicates that the glaciation was global, and that for a period of time in the early Proterozoic the Earth was gripped in an ice age. Following the e
8、arly Proterozoic glaciation, however, the climate appears to have been fairly benign for a very long time. There is no evidence for glaciation for the next 1.5 billion years or so. Then, suddenly, the rock record indicates a series of glacial episodes between about 850 and 600 million year ago, near
9、 the end of the Proterozoic eon. 1. Which of the following does the passage mainly discuss? (A) How patterns in rock layers have been used to construct theories about the climate of the Proterozoic age (B) What some rare fossils indicate about glacial conditions during the late Proterozoic age (C) T
10、he varying characteristics of Proterozoic glacial varves in different parts of the world (D) The number of glacial episodes that the Earth has experienced since the Proterozoic age 2. According to the passage , the fossil record of the Proterozoic eon is (A) highly regarded because it preserves the
11、remains of many kinds of organisms (B) less informative than the fossil record of more recent periods (C) very difficult to interpret due to damage from bacteria (D) more useful to researchers than otheraspects of the rock record 3. The word scarce in line 4 is closest in meaning to (A) ancient (B)
12、tiny (C) available (D) rare 4. It can be inferred from the passage that the principle of uniformitarianism indicates (A) similar conditions produce similar rock formations (B) rock layers in a given region remain undisturbed over time (C) different kinds of sedimentary rocks may have similar origins
13、 (D) each continent has its own distinctive pattern of sediment layers 5. The word resemble in line 14 is closest in meaning to (A) result from (B) penetrate (C) look like (D) replace have similar origins 6. According to the passage , the layers in varves are primarily formed by (A) fossilized bacte
14、ria (B) pieces of ancient dropstones (C) a combination of ancient and recent sediments (D) annual cycles of sediment transport and deposition 7. The phrase the other in line 17 refers to another (A) annual cycle (B) glacial lake (C) layer of sediment (D) season 8. According to the passage , the pres
15、ence of dropstones indicates that (A) the glacial environment has been unusually servere (B) the fine-grained sediment has built up very slowly (C) there has been a global ice age (D) coarse rock material has been carried great distances 9. Why does the author mention Canada, North America, Africa,
16、India, and Europe in lines 23-24? (A) To demonstrate the global spread of dropstones (B) To explain the principles of varve formation (C) To provide evidence for the theory that there was a global ice age in the early Proterozoic eon (D) To illustrate the varied climatic changes of the Proterozoic e
17、on in different parts of the globe 10. Which of the following terms is defined in the passage ? (A) fossil record (line 3) (B) laminae (line 13) (C) varves (line14) (D) glacial episodes (line 28) PASSAGE 92 ABDAC DCCCC 托福阅读真题2 In 1900 the United States had only three cities with more than a million
18、residents New York, Chicago, and Philadelphia. By 1930, it had ten giant metropolises. The newer ones experienced remarkable growth, which reflected basic changes in the economy. The population of Los Angeles (114,000 in 1900) rose spectacularly in the early decades of the twentieth century, increas
19、ing a dramatic 1,400 percent from 1900 to 1930. A number of circumstances contributed to the meteoric rise of Los Angeles. The agricultural potential of the area was enormous if water for irrigation could be found, and the city founders had the vision and dating to obtain it by constructing a 225-mi
20、le aqueduct, completed in 1913, to tap the water of the Owens River. The city had a superb natural harbor, as well as excellent rail connections. The climate made it possible to shoot motion pictures year-round; hence Hollywood. Hollywood not only supplied jobs; it disseminated an image of the good
21、life in Southern California on screens all across the nation. The most important single industry powering the growth of Los Angeles, however, was directly linked to the automobile. The demand for petroleum to fuel gasoline engines led to the opening of the Southern California oil fields, and made Lo
22、s Angeles North America's greatest refining center. Los Angeles was a product of the auto age in another sense as well: its distinctive spatial organization depended on widespread private ownership of automobiles. Los Angeles was a decentralized metropolis, sprawling across the desert landscape
23、over an area of 400 square miles. It was a city without a real center. The downtown business district did not grow apace with the city as a whole, and the rapid transit system designed to link the center with outlying areas withered away from disuse. Approximately 800,000 cars were registered in Los
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- TOEFL 阅读 精选
限制150内