问题 不定项选择

如图所示,虚线a、b、c代表电场中三个等势面,相邻等势面间的电势差相等,实线为一带正电的质点仅在电场力作用下通过该区域时的运动轨迹,P、Q是这条轨迹上的两点,据此可知

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A.三个等势面中,Q点的电势最高

B.带电质点通过P点时电势能较大

C.带电质点通过P点时的动能较大

D.带电质点通过P点时的加速度较大

答案

BD

阅读理解

根据短文内容,判断句子正(T)误(F)。

     Once a circle missed a wedge (楔子). The circle wanted to be whole, so it went around looking for its

missing piece. But because it was incomplete and therefore could roll only very slowly. It admired the flowers

along the way. It chatted with grasses. It enjoyed the sunshine. It found lots of different pieces, but none of

them fit. So it left them all by the side of the road and kept on searching. Then one day the circle found a piece

that fit perfectly. It was so happy. It put the found piece into itself and began to roll. Now it was a perfect

circle, it could roll very fast, too fast to notice the flowers or to talk to the grasses. When it rolled so quickly,

it realized how different the world seemed. Then it stopped, left the found piece by the side of the road and

rolled slowly away.

     The lesson of the story, I suggested, was that in some strange sense we are more whole when we are

missing something. The man who has everything isn't in some ways a whole man. He will never know what

it feels like to yearn (渴望), to hope, to come true the dream of something better.

( )1. At first, the circle couldn't roll fast, because it wanted to chat with the grasses.             

( )2. The circle didn't find the missing piece at last.                                                

( )3. When it was a perfect circle, it rolled too fast to notice the flowers or to talk to the grasses.

( )4. The circle stopped by the side of the road and enjoyed the sunshine.                             

( )5. In some days, a man still will be perfect even if he misses something.                           

单项选择题