问题 不定项选择

磁流体发电是一项新兴技术,它可以把气体的内能直接转化为电能,如图是它的示意图。平行金属板A、B之间有一个很强的匀强磁场,磁感应强度为B,将一束等离子体(即高温下电离的气体,含有大量正、负带电粒子)垂直于B的方向喷入磁场,每个离子的速度为v,电荷量大小为q,A、B两板间距为d,稳定时下列说法中正确的是

[ ]

A.图中A板是电源的正极

B.图中B板是电源的正极

C.电源的电动势为Bvq

D.电源的电动势为Bvd

答案

BD

阅读理解

阅读理解。

     When you see the girl for the first time, you may think she is a boy. She is very outgoing (外向的).

Who is she? Wang Meng,the Chinese top skater.

    On the evening of February 26th, 2010. WangMeng first got to the finishing line in I minute and 29.

213 seconds in the women's 1, 000 meters shorttrack speed skating final (短道速滑决赛) at the

Vancouver Olympic Winter Games (温哥华冬奥会). After she succeeded in the 500-meter and

3, 000meter races,she won her third gold medal this time.With thie one China won four gold medals in

thewomen's short track speed skating.That helped China first win the team gold medal in Winter

Olympics history.

     Just before the final race, Wang Meng caught abad cold and coughed terribly.With the words of

"You can,you can do!"she won at last. She said,"I really feel these three gold medals belong to myteam,

to China. It was with the help of my team thatI won the prize. "

     Though Wang Meng is only twenty-four,she has been the most successful Chinese skater. We are

proud of her and her team. We hope she will be faster in the Sochi Olympics in 2014.

1. China won _____gold medals in the women's short track speed skating.

A. 2  

B. 3  

C. 4  

D. 5

2. It took Wang Meng I minute and 29.213 seconds to finish the_____meters short track

    speedskating final.

A. women's l, 000

B. men's l, 000

C.women's 500

D.men's 500

3. In Wang Meng's opinion,_____ made her winthe prize at last.

A. a strong body  

B. a bad cold

C. her team's help  

D. much exercise

4.Which of the following is NOT true according tothe passage?

A. Wang Mengis very outgoing like a boy.

B. Wang Meng is the most sticcessful Chinese skater.

C. Chinese peopie are proud of Wang Meng and her team.

D. China has got the team gold medal twice in Winter Olympics history.

单项选择题