问题 选择题
如图所示,两根相距为l的平行直导轨ab、cd、b、d间连有一固定电阻R,导轨电阻可忽略不计;MN为放在ab和cd上的一导体杆,与ab垂直,其电阻也为R;整个装置处于匀强磁场中,磁感应强度的大小为B,磁场方向垂直于导轨所在平面(指向图中纸面内);现对MN施力使它沿导轨方向以速度v(如图)做匀速运动;令U表示MN两端电压的大小,则(  )

A.U=vBl,流过固定电阻R的感应电流由b到d

B.U=vBl,流过固定电阻R的感应电流由d到b

C.U=vBl,流过固定电阻R的感应电流由b到d

D.U=vBl,流过固定电阻R的感应电流由d到b

答案

答案:A

阅读理解

When someone says, “Well,I guess I’ll have to face the music”, it doesn’t mean that he is planning to go to hear a singer or attend a concert. It is something far less unhappy than you are called in by your leader to explain why you did this and that or why you did not do this or that.

  At some time or another, every one of us has to “face the music”, especially as children. We can all remember father’s angry words “I want to talk to you”. And only because we did not listen to him. What a bad thing it was!

  In the middle or at the end of every term, we students have to “face the music”. The result of the exam will decide whether we will face the music or not. If...that means parents cold faces and contempt (轻视) of the teachers and classmates.

 “To face the music” is well known to every American, young or old. It is at least 100 years old. It really means that you have to do something, no matter how terrible the whole thing might be, because you know you have no choice.

小题1:“To face the music” means “to__________”.

A.do something that we don’t like to

B.go to the theatre

C.go to the music show

D.do something that we want to小题2:In the third paragraph, “If…”really means “If__________”.

A.we don’t do a good job

B.we get an “A” in the exam

C.the exam is easy

D.the exam is difficult小题3:Which of the following is NOT true according to the passage?

A.“To face the music” is well known in the United States.

B.“To face the music” has a history of more than 100 years.

C.The young Americans know what “to face the music” means.

D.Only the old in the United States know the meaning of “to face the music”.

单项选择题 A1/A2型题