问题 选择题

如图所示的实例中,不属于电磁铁应用的是

答案

答案:D

题目分析:使通电线圈绕在铁芯上就构成了一个电磁铁,故据电磁铁在生活中的应用逐个分析即可判断。A、电磁起重机的主要部分是磁铁,接通电流,电磁铁便把钢铁物品牢牢吸住,吊运到指定的地方,切断电流,磁性消失,钢铁物品就放下来了.故不符合题意;B、据图能看出,电磁阀控制车们两侧有两个电磁铁,也是利用电磁铁来工作的,故不符合题意;C、如图,通电时,电磁铁有电流通过,产生了磁性,把衔铁吸过来,使小锤打击电铃发出声音,同时电路断开,电磁铁失去了磁性,小锤又被弹回,电路闭合,不断重复,电铃便发出连续击打声音,故不符合题意;D、指南针是利用地磁场工作的,故不是利用电磁铁,故该选项符合题意。故选D。

阅读理解

How often one hears children wishing they were grown-ups, and, old people wishing they were young again. Each age has its pleasures and its pains, and the happiest person is the one who enjoys what each age gives him without wasting his time in useless regrets.

Childhood is a time when there are few responsibilities(责任) to make life difficult. If a child has good parents, he is fed, looked after and loved, whatever he may do. It is impossible that he will ever again in his life be given so much without having to do anything in return. What’s more, life is always giving new things to the child——things that have lost their interest for older people because they are too well known. But a child has his pains: he is not so free to do what he wishes to do; he is repeatedly being told not to do something, or being punished for what he has wrongly done.

When a young man starts to earn his own living, he can no longer expect others to pay for his food, his clothes, and his room, but has to work if he wants to live comfortably. If he spends most of his time playing about in the way that he used to as a child, he will go hungry. And if he breaks the laws of society as he used to break the laws of his parents, he may go to prison. If, however, he works hard, keeps out of trouble and has good health, he can have the great happiness of building up for himself his own position in society.

小题1:According to Paragraph 2, the writer thinks that          .

A.life for a child is fairly easy

B.a child is always loved whatever he does

C.if much is given to a child, he must do something in return

D.only children are interested in life小题2:The main idea of the passage is that            .

A.life is not enjoyable since each age has some pains

B.young men can have the greatest happiness if they work hard

C.childhood is the most enjoyable time in one’s life

D.one is the happiest if he can make good use of each age in his life小题3:The paragraph following this passage will most probably discuss           .

A.examples of successful young men

B.how to build up one’s position in society

C.joys and pains of old people

D.what to do when one has problems in life

单项选择题