问题 多选题
理想变压器原线圈接在如图所示的电压上,原副线圈匝数之比为10:1,串在原线圈上的电流表的示数为1A,则以下叙述正确的是(  )

A.变压器输出功率为200W

B.若n1=100匝,则输出端线圈的磁通量变化率的最大值为2Wb/s

C.副线圈两端的电压表示数20V

D.变压器的输入功率是由发电厂的输出功率决定的

答案

AB

完形填空

I played a racquetball game against my cousin Ed last week. It was one of the most __1__ and tiring games I’ve ever had. When Ed first phoned and ___2___ we play, I laughed quietly, figuring on an ___3___ victory. After all, Ed’s idea of ___4___ has always been nothing more ___5___ than lifting a fork to his mouth. ___6___ I can remember, Ed’s been the least physically fit member in the family, and ___7___ proud of himself. His big stomach has always ballooned out between his T-shirt and trousers. Although the family often ___8___ about that, Ed refused to buy a ___9___ T-shirt or to lose weight. So when Ed ___10___ for our game not only with the bottom of his shirt gathered inside his trousers but also with a stomach you could hardly ___11___, I was so surprised that I was ___12___. My cousin must have made an effort to get himself into shape. ___13___, at the point in our game when I’d have predicted(预计) the score to be about 9 to 1 in my favor, it was ___14___ 7 to 9 — and Ed was ___15___. The sudden realization was painful. We ___16___ to play like two mad men. When the score was 16 up, I was having serious ___17___ about staying alive until 21 years old, let alone ___18___ that many points. When the game finally ended, both of us were lying flat on our backs, too tired to ___19___. In a way, I think we both won: I the game, but cousin Ed my ___20___.

1. A. encouraging   B. hopeless     C. surprising   D. regular

2. A. declared B. mentioned  C. persuaded   D. suggested

3. A. unforgettable B. unexpected C. easy    D. early

4. A. exercise  B. preparation C. joy     D. fitness

5. A. time-saving    B. comfortable       C. suitable      D. effort-making

6. A. As soon as     B. As long as  C. When  D. Since

7. A. strangely       B. personally  C. reasonably  D. eagerly

8. A. cared      B. forgot C. quarreled    D. joked

9. A. clean      B. larger  C. straight      D. darker

10. A. set out  B. got ready    C. arrived       D. returned

11. A. notice   B. admire       C. believe       D. measure

12. A. nervous       B. curious       C. careless      D. speechless

13. A. After all       B. As a result  C. Above all   D. At last

14. A. mistakenly   B. then    C. instead       D. naturally

15. A. leading B. coming      C. waiting      D. counting

16. A. pretended     B. stopped      C. continued   D. decided

17. A. thoughts      B. doubts C. situations    D. problems

18. A. scoring B. completing C. receiving    D. keeping

19. A. play     B. start    C. sleep   D. move

20. A. friendship    B. respect       C. support      D. favor

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