下面句子的顺序已经打乱，恰当的语序应该是[ ] ①一高一低 ②跳跃的幅度也略有差

One day, a train was approaching the small town of Cheekyville. On the train was a   1  man with a big suitcase. He was called William Warbler and he looked very   2  indeed. But what made him most unusual was the fact that whenever he needed to   3  , he did so by singing opera. Even if someone said “good day” to him, he would clear his throat and   4  : “Goood dayyy to youuuuuu..... toooooo!”

Almost everyone considered William unusual, since no one could get a normal   5   word out of him. As no one knew how he made his living — he lived quite   6  , always wearing the same old second-hand suit — they often had no ___7__for him and sometimes even made fun of him.

William had been in Cheekyville for some years, when one day a rumor (谣言) spread that William had received a role in a very important   8  in the nation’s capital, that there had been posters everywhere advertising the event, and that it had been a great   9 . And to everyone’s surprise, when William was being interviewed by reporters, he answered their questions by speaking with good   10 , and with a clear and pleasant voice.

From that day on, William gave up   11  at all hours. Now he sang only during his stage appearances. People wouldn’t have thought him   12  if they had seen what William kept in his big suitcase. It was a large   13 , with a hand-carved message on it.

The message said, “Practice every second, for you never know when your   14   will come.” Little did people realize that he only got the role in the opera because the   15   had heard William singing while out buying a newspaper.

1. A. tall       B. sensitive    C. handsome    D. strange

2. A. common     B. concerned   C. wealthy     D. confident

3. A. appear     B. practice     C. communicate D. debate

4. A. whisper   B. respond      C. repeat     D. tease

5. A. advised   B. printed      C. written     D. spoken

6. A. simply     B. naturally    C. calmly      D. fortunately

7. A. mercy     B.  respect     C. trust       D. money

8. A. concert    B. documentary  C. opera      D. film

9. A. experience B. benefit      C. discovery   D. success 

10. A. movements B. manners     C. efforts    D. signs

11. A. pretendingB. recording   C. singing    D. wandering

12. A. mad       B. skillful    C. artificial  D. desperate

13. A. knife     B. stone        C. medal       D. diamond

14. A. solution  B. inspiration  C. performance D. chance

15. A. neighbor  B. visitor     C. director    D. Teacher

甲、乙两位同学沿同一直线推一辆小车，甲用100N的力向右推，乙用60N的力向左推，则小车受到的合力的大小和方向是（　　）

A．40N，向右

B．40N，向左

C．160N向右

D．160N，向左

原丝体

自动复压时，首先开启（）。

A.真空主阀

B.空气复压阀

C.脱气停止

D.氮气复压阀

核酸中的修饰成分(即稀有成分)大部分是在tRNA中发现的。 ( )