选择题_____ the door open.Don't push it.A.Pulling B.Pull C.To pul 答案是选B,A和C为什么不对呢?

问题描述:

选择题_____ the door open.Don't push it.A.Pulling B.Pull C.To pul 答案是选B,A和C为什么不对呢?

这是祈使句,要用动词原形开头.