两块平行金属板带等量异号电荷，要使两板间的电压加倍，而板间的

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问题选择题

两块平行金属板带等量异号电荷，要使两板间的电压加倍，而板间的电场强度减半，可采用的办法有（）

A．两板的电量加倍，而距离变为原来的4倍

B．两板的电量加倍，而距离变为原来的2倍

C．两板的电量减半，而距离变为原来的4倍

D．两板的电量减半，而距离变为原来的2倍

答案

答案：C

判断题

焊缝的基本符号是表示焊缝横截面形状的符号。( )

填空题

用方框中所给单词的适当形式填空。

1. China has developed _______________ in recent years. (rapid)

2. The problem kids in the Hall has given Zack a good chance to ______________. (success)

3. An SOS Children's Village gives helps to the _____________ people. (home)

4. A large population causes many ______________ in India. (difficult)

5. My uncle ______________ in Beijing for more than twenty years. (work)