It was ______ fine weather that they ________ went swimming.
A:such; none
B:such; all
C:so; both
D:so; neither
真空中有两个静止的点电荷,它们之间的作用力为F,若它们的带电量都增大为原来的2倍,距离减少为原来的 12 ,它们之间的相互作用力变为( )