单项选择:Look at the boy running on the playground.Is it David?

问题描述:

单项选择:Look at the boy running on the playground.Is it David?
It __be him .I saw him go to the teachers'office just now.
A must B can't C could D might选那一个

B 都说看见他去老师办公室了 所以那个人不可能是他 选can't