题目

小刚用低倍镜观察到小鱼尾鳍内的血管及血液在血管内的流动情况，如下图所示，其中血流速度最慢的血管是A．1B．2 C．3 D．2和3  答案：B解析:略  阅读理解 　　It doesn't matter when or how much a person sleeps, but everyone needs some rest to stay alive．That's what all doctors thought, until they heard about Al Herpin．Al Herpin, it was said, never slept．Could this be true? The doctors decided to see this strange man themselves． 　　Al Herpin was 90 years old when the doctors came to his home in New Jersey．They thought for sure that he got some sleep of some kind．So they stayed with him and watched every movement he made．But they were surprised．Though they watched him hour after hour and day after day．They never saw Herpin sleeping．In fact, he did not even own a bed．He never needed one． 　　The only rest that Herpin sometimes got was sitting in a comfortable chair and reading newspapers．The doctors were puzzled by this strange continuous sleeplessness．They found only one answer that might explain his condition．Herpin remembered some talk about his mother having been injured several days before he was born．But that was all．Was this the real reason? No one could be sure．Herpin died at the age of 94． (1) The main idea of this passage is that _________． [　　] A． a person was found who actually didn't need any sleep B． large numbers of people do not need sleep C． everyone needs some sleep to stay alive D． people can live longer by trying not to sleep (2) The doctors came to visit Herpin, expecting to _________． [　　] A． cure him of his sleeplessness B． find a way to free people from the need of sleeping C． find that his sleeplessness was not really true D． find out why some old people didn't need any asleep (3) After watching him closely, the doctors came to believe that Al Herpin _________． [　　] A． was too old to need any sleep B． needed no sleep at all C． often slept in a chair D． needed some kind of sleep (4) One reason that might explain Herpin's sleeplessness was _________． [　　] A． that he hadn't got a bed B． that he had gradually got tired of the sleeping habit C． his mother's injury before he was born D． his magnificent physical condition