we _____ have told her the truth英语选择题,

题目

we _____ have told her the truth英语选择题,
选择哪个麻烦解释原因
our motherworried about us very much
we should have told her the truth.
A.must Bshould

答案

B.should
咱妈特别担心咱们.
我们早先应该把实情告诉她的.
should have done用法如下,本题是第2种用法,指本该发生而实际上未发生的情况.
must have done只有推测过去已经发生的情况的用法,在此处不和题意.
should have done只用于谈论过去情况,主要有两个用法：
■用于推测过去已经发生的情况.如：
He should have arrived by now.此时他本该到了.
■用于指本该发生而实际上未发生的情况.
You should have told me so before.你早就应该告诉我.