2014年3月23日第一篇托福阅读真题+题目+答案解析：From Fish to Terrestrial Vertebrates

本次考试的3篇阅读真题，小编都已经拿到，3篇阅读真题分别为Environmental Impact of the Anasazi、Early Modern Industrialization、From Fish to Terrestrial Vertebrates。我们一一来分享。

2014年3月23日第一篇托福阅读真题+题目+答案解析：From Fish to Terrestrial Vertebrates

One of the most significant evolutionary events that occurred on Earth was the transition of water-dwelling fish to terrestrial tetrapods (four-limbed organisms with backbones). Fish probably originated in the oceans, and our first records of them are in marine rocks. However, by the Devonian Period (408 million to 362 million years ago), they had radiated into almost all available aquatic habitats, including freshwater settings. One of the groups whose fossils are especially common in rocks deposited in fresh water is the lobe-finned fish.

1. Paragraph 1 supports which of the following statements about fish evolution?

A. Lobe-finned fish were among the earliest types of fish to appear.

B. Fish began living in freshwater habitats only after originating elsewhere.

C. Lobe-finned fish radiated into almost all available aquatic habitats.

D. During the Devonian, lobe-finned fish were more common in marine than in freshwater habitats.

答案： B

解析： 第一段主要讲地球上最重要的演化之一是鱼从水生转型到陆生。鱼可能起源于海洋，我们最早的证据是在海洋的岩石里。但在Devonian时期，鱼开始基本都呈现水生形式包括淡水，其中一种化石特别普遍在淡水岩石里是lobe-finned fish。选项A中lobe-finned fish显然不是最早的鱼类;选项B与原文中鱼类出现的顺序阐述一致;选项C中的lobe-finned fish只是其中的一种;选项D中的lobe-finned fish是否在海洋比淡水中更普遍在原文中没有做对比。

The freshwater Devonian lobe-finned fish rhipidistian crossopterygian is of particular interest to biologists studying tetrapod evolution. These fish lived in river channels and lakes on large deltas. The delta rocks in which these fossils are found are commonly red due to oxidized iron minerals, indicating that the deltas formed in a climate that had alternate wet and dry periods. If there were periods of drought, any adaptations allowing the fish to survive the dry conditions would have been advantageous. In these rhipidistians，several such adaptations existed. It is known that they had lungs as well as gills for breathing. Cross sections cut through some of the fossils reveal that the mud filling the interior of the carcass differed in consistency and texture depending on its location inside the fish. These differences suggest a saclike cavity below the front end of the gut that can only be interpreted as a lung. Gills were undoubtedly the main source of oxygen for these fish, but the lungs served as an auxiliary breathing device for gulping air when the water became oxygen depleted, such as during extended periods of drought. So, these fish had already evolved one of the prime requisites for living on land: the ability to use air as a source of oxygen.

2. According to paragraph 2, what do the minerals in the delta rocks containing rhipidistian crossopterygian fossils reveal?

A. These deltas formed in dry periods but gradually became wetter.

B.These deltas contain different types of iron minerals than do the surrounding areas.

C.Most rhipidistian crossopterygian fish died when the climate became dry.

D.Rhipidistian crossopterygian fish lived in areas that experienced alternate dry and wet periods.

2. 答案： D

解析： 第二段定位句The delta rocks in which these fossils are found are commonly red due to oxidized iron minerals, indicating that the deltas formed in a climate that had alternate wet and dry periods. 很显然在三角洲的rhipidistian crossopterygian化石里的矿物质揭示了其生活的区域经历了干旱和潮湿交替的时期，选项D正确。

3. The word “advantageous” in the paragraph 2 is closest in meaning to

A. beneficial

B. necessary

C. remarkable

D. common

3.答案： A

解析： advantageous有利的，选项A有益的，选项B必要的，选项C非凡的，选项D普通的，所以选项A正确。

4. In paragraph 2, why does the author include the information that mud inside rhipidistian crossopterygian fossils differed in consistency and texture depending on where the mud was located?

A. To provide evidence that rhipidistian crossopterygian lived in river channels and lakes on large deltas.

B. To identify an effect of the oxidation of iron minerals on the evolution of rhipidistian crossopterygian.

C. To help explain why scientists have concluded that rhipidistian crossopterygian probably had lungs.

D. To explain why scientists decided to cut cross sections through some fossils of rhipidistian crossopterygian.

4. 答案： C

解析： 通过题目中的关键词consistency and texture定位到第二段原句Cross sections cut through some of the fossils reveal that the mud filling the interior of the carcass differed in consistency and texture depending on its location inside the fish. These differences suggest a sadlike cavity below the front end of the gut that can only be interpreted as a lung. 显而易见答案选C，为了解释为什么科学家得到rhipidistian crossopterygian可能有lung肺的结论。

5. 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. Because the lungs of these fish were able to provide only a small amount of oxygen, these fish obtained most of their oxygen through their gills during periods of drought.

B. During periods of extended drought, these fish used their lungs to increase their intake of oxygen beyond the levels absorbed by the gills in normal times.

C. Although these fish primarily used their gills to obtain oxygen, they used their lungs to obtain oxygen from the air when there was not enough in the water.

D. During periods of extended drought, the gills became an auxiliary breathing device and the lungs became the main source of oxygen for these fish

5. 答案： C

2014年3月23日托福阅读真题+题目+答案解析：From Fish to Terrestrial Vertebrates，完整版下载，10元有偿！