一道关于notuntil倒装的英语选择题
Notuntilsomestudentsfailedintheexam__________howmuchtimetheyhadwasted.
A.didn'ttheyrealized
B.didtheyrealize
C.theydidn'trealize
D.theyrealize
我觉得……前面有not了,也就是A、C要排除了吧?我这判断方法对不对?