25. The passage is mainly discussing ____.

　　A.Bill Gates' boyhood

　　B.Lakeside School

　　C.Bill Gates

　　D.Bill Gates and Lakeside

　　Ⅳ.Reading Comprehension

　　From the earliest times there are records of dolphins(海豚) helping and caring for men. Although they can even kill sharks, they have never been known to attack a human being,rather they have helped men in difficulty on the sea. Dolphins' brains are 30 percent larger than those of people, and are equally complex. During experiments dolphins have learnt to perform tasks that require logical reasoning, so their intelligence is unquestionable.Furthermore, fossil evidence reveals that they have had their larger brains for thirty million years, compared to around a million years for man.

The dolphin ancestors lived upon the land, and dolphins are mammals(哺乳动物) like us, they feed their babies on milk, and breathe air like us. They appear to care for each other, for example if a dolphin is ill, its companions will help it up to the air so that it can breathe. The sounds they make also appear to be some kind of communication.

　　It seems that we have discovered an animal that may be close to us in intelligence, and furthermore one that is friendly, co-operative,and which has emotions similar to our own. How do we treat these animals? So far man has killed six million dolphins, and every year tens of thousands more are killed.

　　26. Which of the following statements best expresses the main idea of the passage?

　　A.Dolphins are human beings' best friends.

　　B.Dolphins have larger brains than that of human beings.

　　C.Dolphins are as clever as human beings.

　　D.Dolphins are quite close to human beings in many ways.

　　答案： D

　　[解析]此题是要旨题，提问的是文章的中心大意。就自学考试而言，文章或段落的主旨通常以主题句的形式出现。那么如何辨别主题句呢?文章的主题句一般是文章的第一句，但有时也出现在文章的中部或甚至文章尾部。本篇文章的主题句即出现在第三自然段的开头。在这篇文章中，作者在第一自然段中谈到了海豚的智力跟人类的十分相似，在第二自然段中又谈到海豚的生活方式跟人类的也有很多相似之处。故D是正确答案。