一道英语过去完成时题~Helen ________ her key in the office so she had to wait until her husband _______ home.A.has left; comes B.left; had come C.had left; came D.had left; would come第二个空填什么时态比较正确?为什么第二个空要使用过去式?

问题描述:

一道英语过去完成时题~
Helen ________ her key in the office so she had to wait until her husband _______ home.
A.has left; comes B.left; had come C.had left; came D.had left; would come
第二个空填什么时态比较正确?
为什么第二个空要使用过去式?

C

选C

C.因为这道题本来就是过去时,而过去已经完成的动作当然要用过去完成时.过去完成时;had+过去分词.所以第一个空填had.第二个空可用排除法,A是一般现在时态,是错的.D也不能用于过去时态.剩下的选项可根据until来判断,句意是:她不得不等着,直到她的丈夫回来,说明那时丈夫还没回来,所以不能用过去完成时.

C. had left; came
第二个空填过去式