—Were you at home yesterday?
—No, I________. I was ________ school.
A:
wasn't;at
B:
weren't; at
C:
weren't;in
D:
wasn't;in
0乘351和0+351的结果( )
如图所示为点电荷a、b所形成电场的电场线分布图(箭头未标出),在M点处放置一个电荷量大小为q的负试探点电荷,受到的电场力大小为F,以下说法中正确的是( )