by the time the earthquake ended,millions of people had become ho_英语解答

by the time the earthquake ended,millions of people had become homeless.
为什么加had?
直接became可以吗？

人气：175 ℃　时间：2019-12-13 15:15:58

解答

直接became不可以.因为by the time 是过去完成时的标志,看见这个标志,就一定要用过去完成时.过去完成时的标志有：1、by + 时间点 By last year,we had learnt 2 000 English words.2、by the time + 句子,就是上面这...