2021年全国研究生入学考试英语押题试卷（一）4

1、XX年全国研究生入学考试英语押题试卷（一）4 三、单项选择题（每题2分，共10分）选择下列答案中正确的一个，选择您认为正确的答案 Long before Man lived on the Earth, there were fishes, reptiles, birds, insects, and some _m _ls. Although some of these ani _ls were an _stors of kinds living today, others are now extinct, that is, they have no des _ndants alive now.

2、 41)Very oasionally the rocks show impression of skin, so that, apart from color, we can build up a reasonably aurate picture of an ani _l that _d millions of years ago. That kind of rock in which the re _ins are found _s us much about the nature of the original land, often of the plants that grew o

3、n it, and even of its cli _te. 42)_Nearly all of the fossils that we know were preserved in rocks formed by water action, and most of these are of ani _ls that lived in or near water. Thus it follows that there must be _ny kinds of _m _ls, birds, and insects of which we know noting. 43) There were a

4、lso crablike creatures, whose bo _s were covered with a horny substan _. The body segments each had two pairs of legs, one pair for walking on the sandy bottom, the other for swimming. The head was a kind of shield with a pair of pound eyes, often with thousands of lenses. They were usually an inch

5、or two long but some were 2 feet. 44)_Of these, the ammonites are very interesting and important. They have a shell posed of _ny chambers, each representing a temporary home of the ani _l. As the young grew larger it grew a new chamber and sealed off the previous one. Thousands of these can be seen

6、in the rocks on the Dorset Coast. 45)_ About 75 million years ago the Age of Reptiles was over and most of the groups _d out. The _m _ls quickly developed, and we can tra _ the evolution of _ny familiar ani _ls such as the elephant and horse. Many of the later _m _ls though now extinct, were known t

7、o primitive _n and were featured by him in cave paintings and on bone carvings. AThe shellfish have a long history in the rock and _ny different kinds are known. BNevertheless, we know a great deal about _ny of them because their bones and shells have been preserved in the rocks as fossils, From the

8、m we can _ their size and shape, how they walked, the kind of food they ate. CThe first ani _ls with true backbones were the fishes, first known in the rocks of 375 million years ago. About 300 million years ago the amphibians, the ani _ls able to live both on land and in water, appeared. They were

9、giant, sometimes 8 feet long, and _ny of them lived in the swampy pools in which our coal seam, or layer, or formed. The amphibians gave rise to the reptiles and for nearly 150 million years these were the principal forms of life on land, in the sea, and in the air. DThe best index fossils tend to b

10、e _rine creature. There ani _ls evolved rapidly and spread over large over large areas of the world. EThe earliest ani _ls whose re _ins have been found were all very _ kinds and lived in the sea. Later for _ are more plex, and among these are the sea-lilies, relations of the star-fishes, which had

11、long arms and were attached by a long stalk to the sea bed, or to rocks. FWhen an ani _l _s,the body,its bones,or shell, _y often be carried away by streams into lakes or the sea and there get covered up by mud .If the ani _l lived in the sea its body would probably sink and be covered with mud .More and more mud would fall upon it until the bones or shell bee embedded and preserved. GMany factors can influen _ how fossils are preserved in rocks. Re _ins of an organi _ _y be repla _d by minerals, dissolved by an acidic soluti