2010年考研英语七选五技巧

3)代词线索

　　英语表达中代词出现的频率极高，代词的作用无非是指代前面提及的名词或形容词概念，巧妙利用这样的指代关系和根据代词的单复数差异可以准确而快速地解题。

　　例(大纲样题)

　　There were also crab-like 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。
　　〔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, 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 creatures. These 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 forms 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。

　　【解析】〔A〕 下文一开始就出现了指示代词these，这说明试题前面的句子表明了一类事物，也就是说，试题部分应该有“some, several, many”或类似的词，对比答案只能是选项〔A〕 The shellfish have a long history in the rock and many different kinds are known.〔A〕里面出现了many different kinds of，这个短语和后面的指示代词these形成了对应关系。