A.Here you are.
B.Yes, I want a bird.
C.That's right.
D.I'm six.
E.How nice!
(____)1.Two and three is five.
(____)2.This doll is for you.
(____)3.I want a pencil.
(____)4.How old are you?
(____)5.Please make a wish, Mike.
如图是质谱仪的工作原理示意图,带电粒子被加速电场加速后,进入速度选择器.速度选择器内相互正交的匀强磁场和匀强电场的强度分别为B和E.平板S上有可让粒子通过的狭缝P和记录粒子位置的胶片A1A2.平板S下方有强度为B0的匀强磁场.下列表述正确的是( )