A:can you
B:will you
C:shall we
D:may we
He____ ____ while having a P.E. class.
—____ coat do you like, the red one ____ the green one?
— I like this____one.
一束离子能沿入射直线方向通过互相垂直的匀强电场和匀强磁场区域,然后进入磁感应强度为B′的偏转磁场内做半径相同的匀速圆周运动(如图),则这束离子必定有相同的____,相同的____.