临氢系统泄漏时，应选用（）。A.1#滤毒罐 B.3#滤毒罐 C.4#滤毒罐 D.长管

You have often __1__ people talk about work. Perhaps you have __2__ your friends about how hard you worked to get something done. However, you may have done no work __3_ you think you worked hard.
A boy is pushing a big box very hard, but the box is __4__ heavy for him to move and he may __5__ to push against the box. __6__ the language of science, he has not done __7__ work. Can you think you are working when you are studying or talking?
In science, work is only done when a force(力) moves something that has weight through a distance（距离）.
Work =" force" × distance moved.
__8_ you want to find out whether work is done, _9_ yourself, “Is a push or a pull moving something through a distance?” If your answer is __10_, then work is being done.

小题1:	A．asked B．wanted C．listened D．heard

小题2:	A．said B．told C．talked D．spoken

小题3:	A．though B．so that C．while D．because

小题4:	A．very B．so C．too D．such

小题5:	A．be afraid B．be sure C．not like D．like

小题6:	A．In B．With C．As D．For

小题7:	A．a B．no C．some D．any

小题8:	A．If B．After C．While D．As soon as

小题9:	A．to ask B．just ask C．only think D．to think

小题10:

A．“Right” B．“Good” C．“Well” D．“Yes”