4.“交的补等于补的并，即”；“并的补等于补的交，即”.

3.对于含有个元素的有限集合，其子集、真子集、非空子集、非空真子集的个数依次为 　

2.对集合，时，你是否注意到“极端”情况：或；求集合的子集时是否注意到是任何集合的子集、是任何非空集合的真子集.L

1.集合的元素具有无序性和互异性.

　　 Most children like watching 　　1　 　. It’s very interesting .By watching TV they can see and learn a lot and know many things 　　2　 　their country and the 　3　　 　. Of course, they can also learn over the radio. But they can learn 　4　　 　and more easily on TV. Why? 　　5　 　they can hear and watch at the same time. But they can’t 　　6　 　anything over the radio. TV helps to open their minds, too. They learn newer and better ways of 　7　 　things. Many children watch TV only on 　8　　 　or Sunday evening. They are always busy with their lessons. But some children watch TV every night. They go to bed very 　　9　 　. They can’t have a good 　10　　 　. How about you, my young friend?

1.(　　 )A.recorder　 B.radio　 C.TV　 D.Mp4

2.(　　 )A.of　　 B. for　　 C.at　 D.about

3.(　　 )A.school　 B.classroom　 C.playground　 D.world

4.(　　 )A.good　 B. well　 C.better　 D.best

5.(　　 )A.Because　 B.But　 C.Where　 D.Whether

6.(　　 )A.hear　　 B.look　　 C.see　　 D.listen

7.(　　 )A.do　　　 B.doing　　 C.does　 D.did

8.(　　 )A.Thursday　 B.Monday　 C.Tuesday　 D.Saturday

9.(　　 )A.late　　 B.early　 C.latest　 D.earliest

10.(　　 )A.hobby　 B.rest　 C.sport　 D.teahcer

7. There is a snow tomorrow.(用一般将来时改写)

There 　　　　　　　　　　　a snow tomorrow.

8 John was sleeping at ten last night.(对划线部分提问)

　________　 _______　 John　 ________ at ten last night?