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问题 不定项选择

汽车在平直公路上行驶，在它的速度从0增大到v的过程中，汽车发动机做的功为W1；在它的速度从v增大到2v的过程中，汽车发动机做的功为W2，设汽车在行驶过程中发动机的牵引力和所受阻力都不变，则[ ]

A．W2=2W1

B．W2 =3W1

C．W2 =4W1

D．仅能判定

答案

答案：B

改错题

Never shall I forget the first English lesson giving by Miss Liu. One Monday morning, when she entered into the classroom, we found that she was young and beautiful lady. Then she introduced her and said we shouldn’t call her Teacher Liu but Miss Liu. Late, she let us go to the blackboard and said something about ourselves in English in turn. When it was my turn, I felt too shy that I didn’t dare to say anything before the class. She went up to me and said kind, “Don’t be afraid. I believe you could do it well.” At last, I went to the blackboard. She praised me for that I had done.

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单项选择题 A1/A2型题

室间隔缺损常不伴有（）

A.心悸

B.气短

C.腹胀

D.心律失常

E.感染性心内膜炎
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