C．has a great deal of trouble doing mental arithmetic

　　D．comes up with solutions in most natural ways

　　答案：B细节理解题。根据最后一段第一句，并结合第二句

　　"One of the outstanding and essential qualities required is self－discipline, a quality I lack."可知，作者认为自己不是科学家，因为一个科学家的基本素质就是有自律能力，但作者恰恰缺乏这一点。故选B项。

　　4．The author couldn't remember his relatives clearly

　　because________ .

　　A．he didn't live very long with them

　　B．he was too young when he lived with them

　　C．the family was extremely large

　　D．he was fully occupied with observing nature

　　答案：D推理判断题。第二段作者回忆了在农场度过的日子，对于那里的狗、鸟等动物作者至今仍历历在目，但对那里的亲戚、房子、玩具已记不清了，可见他从小就专注于观察自然界中的一切，其他事情他几乎很少关注。故选D项。

　　B

　　Early one morning, more than a hundred years ago, an American inventor called Elias Howe finally fell asleep. He had been working all night on the design of a sewing machine but he had run into a very difficult problem: It seemed impossible to get the thread to run around the needle without any problems.

Though he was tired, Howe slept badly. He turned and turned. Then he had a dream. He dreamt that he had been caught by terrible savages whose king wanted to kill him and eat him unless he could build a perfect sewing machine. When he tried to do so, Howe ran into the same problem