- Do you think the rain will stop tomorrow?
-__________. It has rained for ten days. It's too wet everywhere.
A:I hope not
B:I'm sure it is
C:I'm afraid it will
D:I hope so
如图,一带负电荷的油滴在匀强电场中运动,其轨迹在竖直平面(纸面)内,且相对于过轨迹最低点P的竖直线对称.忽略空气阻力.由此可知( )