The glass and bricks____(fall)down when they realized it was an earthquake.动词填空 答案是have fallen 为什么不是were falling
问题描述：
The glass and bricks____(fall)down when they realized it was an earthquake.动词填空 答案是have fallen 为什么不是were falling
答
强调已经倒下了
答
这句话的意思是当他们意思是地震的时候，玻璃和砖块已经掉下来了
答
when在引导时间状语从句时结构有be doing when did
而在此句中,强调玻璃砖块先落下,然后他们才意识到地震来临,玻璃砖块落下这个动作在发现地震来临前发生.所以用现在完成时,而were falling是二者一同发生,不符愿意
答
have fallen