In the following text, 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 blanks. There are two extra choices, which do not fit in any of the blanks. 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.
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.
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 nothing.
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.
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.
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 sealilies, relations of the starfishes, 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.
42.本题考查寻找特征词的能力。在该题中，根据就近原则在该题后的句子中找到"the fossils"和"water action"为特征词。"the fossils"说明"fossils"一词是至少是第二次出现，因为它前面加了定冠词the，通过仔细观察并不难发现，42以及其前面的内容中都没有fossils，这就确定fossils一词必定出现在41，42中。根据意群相一致原则，在42中必定要与"water action"同现或复现的语言点。综上所述，有同时满足以上两个条件的选项才是正确答案。虽然[G]项一开始就有"how fossils are preserved", 但是[G]项讲的是动物遗体上的有机组织转化形式，没有提及水的活动。选项［F］中就多次提到水在化石形成过程中的重要作用，与上下文相符合。
43.本题选择的特征词是"also"。"also"表并列关系，这就证明在43前面的句子中应当与also后的crablike creatures相并列，即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.本题选择的特征词是these以及与其具有同指关系的ammonites 和They 。通过阅读44以后的两个句子不难发现，these，ammonites ，They是指同一事物，意即有"shell"的事物。同时44后一开始就有"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",为避免句式上的重复，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.该题目是一道简单试题，一方面这是一道段落题，这就决定了有可能选最长的选项为答案，另一方面根据就近原则在下一段首句中发现的About 75 million years ago成为我们解题的关键。从文章的整体结构看，这里需要一个内容的"高潮"：前面几段，动物都在不断地进化，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 air"。所以正确答案只能是[C]。