第一篇（样题）

　　Directions:

　　In the following article, some sentences have been removed. For Questions 41-45 ,choose the most suitable one from the list A-G to fit into each of the numbered blank. There are two extra choices ,which do not fit in any of the gaps .Mark your answers on ANSWER SHEET 1.(10 points)

　　Long before Man lived on the Earth , there were fishes ,reptiles, birds, insects, and some mammals. Although some of these animals were ancestors of kinds living today ,others are now extinct, that is, they have no descendants alive now .

　　41) Very occasionally the rocks show impression of skin, so that, apart from color, we can build up a reasonably accurate picture of an animal that died millions of years ago. That kind of rock in which the remains are found tells us much about the nature of the original land ,often of the plants that grew on it, and even of its climate.

　　42)____Nearly all of the fossils that we know were preserved in rocks formed by water action, and most of these are of animals that lived in or near water. Thus it follows that there must be many kinds of mammals, birds, and insects of which we know noting.

　　43) There were also crablike creatures, whose bodies were covered with a horny substance. 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 compound eyes, often with thousands of lenses. They were usually an inch or two long but some were 2 feet.

　　44)____Of these, the ammonites are very interesting and important .They have a shell composed of many chambers , each representing a temporary home of the animal .As the young grew larger it grew a new chamber and sealed off the previous one .Thousands of these can be seen in the rocks on the Dorset Coast .

　　45)____ About 75 million years ago the Age of Reptiles was over and most of the groups died out .The mammals quickly developed, and we can trace the evolution of many familiar animals such as the elephant and horse . Many of the later mammals though now extinct ,were known to primitive man and were featured by him in cave paintings and on bone carvings .

　　[A]The shellfish have a long history in the rock and many different kinds are known.

　　[B]Nevertheless , we know a great deal about many of them because their bones and shells have been preserved in the rocks as fossils ,From them we can tell their size and shape ,how they walked ,the kind of food they ate .

　　[C]The first animals with true backbones were the fishes ,first known in the rocks of 375 million years ago .About 300 million years ago the amphibians ,the animals able to live both on land and in water , appeared. They were giant ,sometimes 8 feet long ,and many 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 .

　　[D]The best index fossils tend to be marine creature .There animals evolved rapidly and spread over large over large areas of the world .

　　[E]The earliest animals whose remains have been found were all very simple kinds and lived in the sea. Later forma are more complex ,and among these are the sea-lilies , relations of the star-fishes ,which had long arms and were attached by a long stalk to the sea bed ,or to rocks .

　　[F]When an animal dies ,the body ,its bones ,or shell ,may often be carried away by streams into lakes or the sea and there get covered up by mud .If the animal 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 become embedded and preserved .

　　[G]Many factors can influence how fossils are preserved in rocks .Remains of an organism may be replaced by minerals, dissolved by an acidic solution to leave only their impression, or simply reduced to a more stable form .

　　本篇介绍的是史前类动物。文章结构的脉络清晰：首先介绍什么是史前动物和我们研究史前动物的依据——化石，以及化石形成的过程。随后，作者即按照动物进化的顺序——我们可以见到其化石的最早的动物，水生壳类动物，脊椎类动物——逐一加以介绍。

　　41．文章一开始，作者告诉我们，早在人类出现以前地球上就许多物种，现在有些物种的后代依然生存，而另外一些则没有留下后裔。在本题空白处后面文章又说岩石上偶尔会留下数百万年前就死掉了的动物精确的印记。显然，空白处应该是关于岩石与灭绝了的动物之间的关系（7个选项中有A﹑B﹑E﹑G四项提到了“rock”,但另外大三项意思上不符）。此外，空白处前面的“extinct”和“no descendant”均为否定意义和表达，而空白处的后面“accurate”和“much”则为肯定意义的表达；这意味着空白处的内容应该有一个结构上的“转折—只有B项符合这一条件。所以正确答案只能是B。

　　42．本题具有相当的难度。由于G项一开始就有“how fossils ate preserved” ,与上文和下文似乎都是相吻合的；但是G项后面讲的是动物遗体上的有机组织“organism”可能转达化成几种形式而本题空白处后面的内容则告诉人们“Nearly all of the fossils that we know were preserved in rocks formed by water action”(岩石中几乎所有的化石都是由于水作用泥沙对于化石保存下来所起的作用—与上下文相符合。

　　43．本题选择的线索有两条：下文中有“There were also crab-like creatures …’,空白处显然有关于另一动物的内容；从本段开始，文章转向讨论由低级高级变化（进化）中的动物。E项开始的部分是“The earliest animals whose remains have been found…”,符合文章写作的顺序。B项与上文相符，但与下文不符，且与全文结构不相吻合。

　　44．本题选择的主要根据是：下文一开始就有“Of these,…”,也就是说，空白部分应该有“some, several, many”或类似的词，答案只能是A。由于文中有了“The first animals”,为避免句式上的复，作者改变句子起始的模式—这种做法很多见，因而也是考生阅读和写作中应该注意的。

　　45．从文章的整体结构看，这里需要一个内容的“高潮”：前面几段，动物都在不断的进化，而下文中“About 75 million years ago the Age of Reptiles was over”,这里需要有一个“交代”。只有C项符合这一条件；同时，“reptile”在本题空白处前文章中从没有提到，在下文中又没有作为新信息，因而作为正确答案的选项中一定有这个词，只有C项中有“The amphibians gave rise to the reptiles for nearly 150 million years these were the principal forms of life on land, in the sea, and in the sea ,and in the air”。所以正确答案只能是C。

　　（解释的资料来源于全国硕士研究生入学统一考试英语考试分析）