A:沿着电场线方向,电势一定越来越低
B:电场强度为零的点,电势一定为零
C:电场强度处处相同的区域内,电势也一定处处相同
D:只在电场力作用下,正电荷一定从高电势的地方向低电势的地方移动
—Excuse me. Is the library open all day?
— . Only from 8 a.m. to 4 p.m.