研究对象是随机分组的是（）。 A.病例-对照研究 B.队列研究 C.流行病学实验研究

阅读理解。

     Harry likes talking too much. His father doesn't like him talking at table. One day at dinner,

     Harry is ready to say something, but his father stops him.

     After a while, they almost finish their dinner. Father asks,"Hi, my boy, what are you going

to say?"

     "Dad, is a fly delicious?" says Harry. "Of course not," says his father. "Why do you ask me that?"

    "A fly was in your bowl just now and you swallowed(吞)it,"says Harry. "Why didn't you

tell me earlier?"

     "You stopped me!"

( )1. At dinner a fly was in Harry's father's bowl.          

( )2. Harry likes talking only at table.                      

( )3. Harry asked his father if a fly was delicious.          

( )4. His father likes eating flies.                          

( )5. Finally, his father knew he ate a fly and was very happy.

担任县（市）委书记、县（市）长职务以及县（市）纪检机关、组织部门、人民法院、人民检察院和公安部门主要领导职务的，一般不得在（）任职。

某同学分别用如图所示 的（a）、（b）两种方法挑着同 一个物体行走，（a）图中肩受到的压力_______（b）图中肩受到的压力；（a）图中手施加的动力______（b）图中手施加的动力 （填“大于”“等于”或“小于”）。

如图是神经元模式图，请根据图回答：

神经元的基本结构包括______和______两部分，神经纤维是由______和套在外面的______共同构成的．神经元的功能是______．

闸刀开关在安装时，不得倒装或平装，手柄要向（）。

A.左

B.下

C.上