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问题 选择题
如图所示，两极板与电源相连接，电子从负极板边沿垂直电场方向射入匀强电场，且恰好从正极板边沿飞出，现在使电子入射速度变为原来的两倍，而电子仍从原位置射入，且仍从正极板边沿飞出，则两极板的间距应变为原来的（    ）

A．2倍

B．4倍

C．

1/2倍

D．

1/4倍

答案

答案：C

问答题

Once you’ve written down all your goals, both large and small, the next step on your journey to success is to activate the creative powers of your subconscious mind by reviewing your list two or three times every day. Take time to read your list of goals. Read the list one goal at a time. Close your eyes and picture each goal as if it were already accomplished. Take a few more seconds to feel what you would feel if you had already accomplished each goal.
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多项选择题

滑石用治暑湿、湿温，是取其什么功效（）。

A.利水湿

B.化湿

C.收湿敛疮

D.行气

E.解暑热
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