四级考试阅读备考笔记（30）

　　17. The author suggests that the sonar system of bats ____

　　A) was at the height of its perfection 50 million years ago

　　B) is better than man-made sonar because it has had 50 million years to be be refined

　　C) should have been discovered by man many years ago

　　D) is the same as it was 50 million years ago

　　注：B 选项体现一段结尾和二段开头，应该优选，含有关系词 because,although,not only...but also, as well as 的应该优选

　　18. Echo location in this article means the _____.

　　A) location of echoes

　　B) ability to determine where an echo comes from

　　C) scientific term for sound waves

　　D) ability to locate unseen objects by echoes

　　注：1.A 为干扰选项，过于表面化。

　　2.B 项为等价选项所以为错误。

　　To appreciate the precision of the bats echo location, we must first consider the degree of their reliance upon it. Thanks to sonar, an insect-eating bat can get along perfectly well without eyesight. This was brilliantly demonstrated by the Italian naturalist

　　Lazzaro Spallanzani. He caught some bats in a bell tower, blinded them and released them outdoors. Four of these blind bats were recaptured after they had found their ways back to the bell tower, and on examining their stomachs contents, Spallanxani found that they had been able to capture and eat flying insects. We know from experiments that bats easily find insects in the dark of night, even when the insects make no sound that can be heard by human ears. A bat will catch hundreds of softbodied silent flying insects in a single hour. It will even detect and chase pebbles tossed the deficiencies of man-made sonar

　　B) the dependence of man upon animals

　　C) that we are living in a machine age

　　D) that the sonar system of bats is remarkable

　　注：写作目的题型，写作目的=写作动机+文章主题，看文章主题第一句话。

　　20. The following is the main point of the article:____

　　A) A bat will catch hundreds of insects in a single hour.

　　B) There is a perfection in nature which sometimes can not be matched by mans creative efforts.

　　C) The phrase blind as a bat is valid.

　　D) Sonar and radar systems of man are inefficient.

　　注：写作主题题型，第一句话的同义改写 match v. 匹敌。