问题 填空题

在照明电路的两根导线中,用测电笔接触其中一根,发现测电笔上氖管发光,这根线是 ______线.在照明电路中使用洗衣机时,出于安全考虑,常使用三孔插座,其中有一根线与洗衣机的外壳相连,它是 ______线.

答案

(1)手接触试电笔笔尾金属体,笔尖接触火线或零线.氖管发光的是火线,氖管不发光的是零线.

(2)三孔插座的上孔接地线,左孔接零线,右孔接火线.三脚插头的上端的一脚和地线相连,三脚插头的上端的一脚和用电器金属外壳相连,如果用电器漏电,人接触用电器时,人体和地线并联,人体被短路,没有电流通过人体,不会对人体造成伤害.

故答案为:火;地.

阅读理解

One hot night last July, when our new baby wouldn’t or couldn’t sleep, I tried everything I could think of: a warm bottle, songs gentle rocking. Nothing would settle him. Guessing that I had a long night ahead of me, I brought a portable TV into his room, figuring that watching the late movie was as good a way as any to kill of the hours till dawn. To my surprise, as soon as the TV lit up, the baby quieted right down, and his little eyes focused brightly on the tube. Not to waste an opportunity for sleep, I then tiptoed out of the room, leaving him to watch the actors celebrate John Bellushi’s forty-fifth birthday.

My wife and I heard none of the baby that night, and the next morning when I went into his room, I found him still watching TV himself.

I found in my baby’s behavior a symbol of the new generation. My wife and I had given him some books to examine, but he merely spit upon them. When we read to him, he did not feel comfortable. And so it is in the schools. We find that our students don’t read and they look down upon reading and scold those of us who teach it. All they want to do is watch TV. After this experience with the baby, however, I have reached a conclusion: “Let them watch it!” If television is that much more attractive to children than books, why should we fight about it? Let them watch it all they want!

小题1:Why did the author bring a TV set into his son’s room?

A.To make his son keep quiet.   

B.To spend the night by watching TV programs.

C.In order not to let his son feel lonely.

D.To make his son go to sleep as soon as possible.小题2:The baby’s reaction to the TV program was _______ for the writer.  

A.unexpected

B.encouraging

C.exciting

D.calm小题3:From this passage we know that the author is probably           .

A.a doctor

B.a reporter

C.an editor

D.a teacher小题4:According to the passage, which is true of the school children?

A.They prefer reading to watching TV.   

B.They like watching TV after school.

C.They would rather watch TV than read books.

D.They like their teachers who teach them reading.

问答题