问题
不定项选择
下列说法正确的是 [ ]
A．电荷放在电势高的地方，电势能就大
B．无论正电荷还是负电荷，克服电场力做功它的电势能都增大
C．正电荷在电场中某点的电势能，一定大于负电荷在该点具有的电势能
D．电场强度为零的点，电势一定为零
答案
答案：B
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下列说法正确的是 [ ]
A．电荷放在电势高的地方，电势能就大
B．无论正电荷还是负电荷，克服电场力做功它的电势能都增大
C．正电荷在电场中某点的电势能，一定大于负电荷在该点具有的电势能
D．电场强度为零的点，电势一定为零
答案：B
It was a Sunday afternoon. It was very __and nobody wanted to stay at home. Mike decided to go swimming in the river. His brother,Jim.wanted to go with him. “___him with you, Mike” said their father.” he will do what you say, I think.” They got _the river quickly. A lot of people were __in it. Mike told Jim to play in the bank,then he __into the river. About an hour later, Mike swam to the bank with a fish in his hand. Jim was very ___. He found a bottle and put the fish in it. Jim did__except(除了) watching the fish that evening. Suddenly Mike heard Jim__in the room. He ran to him and asked,” what’s wrong__you, Jim?” “ The fish has died,” Jim said “I thought it was ___. So I took it out of the bottle and put it on the chair, I only wanted it to have a rest.”
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