Windows的文件夹结构是一种（）。A、关系结构B、网状结构C、对象结构D、树状结

PET应用的是下列哪个粒子来成像（）。

A.正电子

B.单光子

C.X射线

D.α粒子

E.β粒子

A special laboratory at the University of Chicago is busy only at night. It is a dream laboratory where researchers are at work studying dreamers. Their findings have discovered that everyone dreams from three to seven times a night, although in ordinary life a person may remember none or only one of his dreams.

　　While the subjects—usually students—sleep, special machines record their brain waves and eye movements as well as the body movements that signal the end of a dream. Surprisingly, all subjects sleep soundly.

Observers report that a person usually fidgets(烦躁不安) before a dream. Once the dream has started, his body relaxes and his eyes become more active, as if the curtain had gone up on a show. As soon as the machine shows that the dream is over, a buzzer wakens the sleeper. He sits up, records his dream, and goes back to sleep—perhaps to dream some more.

Researchers have found that if the dreamer is wakened immediately after his dream, he can usually recall the entire dream. If he is allowed to sleep even five more minutes, his memory of the dream will have disappeared.

小题1:According to the passage, researchers at the University of Chicago are studying ____.

A．contents of dreams　

B．dreamers while they dream

C．the meaning of dreams

D．the progress of sleeping小题2:Their finding has discovered that _____.

A．everyone dreams every night

B．dreams are easily remembered

C．dreams are likely to be frightening

D．One person dreams only one dream a night小题3:The machines being used in the experiment record _____.

A．the depth of sleep

B．the subjects’ brain waves and eye movements

C．how many dreams a person has

D．what a sleeper dreams during his sleep小题4:A person would be most likely to remember the dream that _____.

A．was of most interest to him

B．occurred immediately after he went to sleep

C．occurred just before he woke up

D．was the longest one to him

从词类活用的角度看，下列句中加粗词归类正确的一项是   [ ]

①外连衡而斗诸侯

②有席卷天下，包举宇内，囊括四海之意

③诸侯恐惧，会盟而谋弱秦

④然陈涉瓮牖绳枢之子，氓隶之人

⑤焚百家之言，以愚黔首

⑥序八州而朝同列

⑦天下云集响应，赢粮而景从

A.①⑤／②⑦／③⑥／④

B.①③⑤／②④／⑥⑦

C.①③⑤⑥／②⑦／④

D.①⑤⑥／②⑦／③④

用力F把质量为m的物体从地面由静止开始举高h时物体的速度为v，则（　　）

A．力F做功为mgh

B．重力做功为-mgh

C．合力做功为

D．力F做功为

洋地黄中毒引起的心律失常最常见的是（）

A.房性期前收缩

B.室性期前收缩

C.室上性心动过速

D.室性心动过速

E.房室传导阻滞