1930. This was also a time when a new material was made. Nylon came out in 1935. It changed the kind of clothes people wear. The middle part of the 20th brought new ways to help people get over diseases. They worked very well. They made people healthier and let them live long lives. By the 1960s most people could expect to live to be at least 60. By this time most people had a very good life. Of course new inventions continued to be made. But man now had a wish to explore again. The world is known to man but the stars are not yet. Man began looking for ways to go into space. Russia made the first step. Then the United States took a step. Since then other countries，including China and Japan，have made their steps into space.

24．The first great invention ever known was ________.

A．the camera B．the wheel

C．the electric light D．the radio

答案　B　[细节理解题。根据第一段第二句"The first great invention was one that is still very important today-the wheel. "可知，已知的第一个最伟大的发明就是轮子。故选B。]

25．Which of the following was turned out nearly at the same time with the jet plane?

A．The radio. B．The camera.

C．Nylon. D．The helicopter.

答案　C　[细节理解题。根据第二段中的句子"The helicopter in 1909. Sound movies in 1926. The computer in 1928，and jet planes in 1930. This was also a time when a new material was made. Nylon came out in 1935. "对比四个选项可知，Nylon的发明时间与喷气飞机的发明时间最为接近。文中没有关于收音机和相机的具体发明时间的描述，故选C。]

26．This passage talks mainly about ________.

A．how inventions affect (影响) people's life

B．when electric light was invented

C．which country made the first step into space

D．why cars were very important

答案　A　[主旨大意题。通读全文可知，这篇短文主要讲述了人类有史以来的一些重大发明以及这些发明对人类生活的影响。故选项A"发明如何影响人类的生活"为本文主题。]