题目内容
Not until he failed in the examination _______ Cliff ______ the importance of careful preparation.
A.had; realized B.did; realize C.was; realized D.has; realized
B

练习册系列答案
相关题目
It was not until I came here ____ I realized this place was famous, for not only its beauty but also its weather.
A.who |
B.that |
C.where |
D.before |