问题
Not until ________ in the college entrance exam ________ that he had wasted much time using his mobile phone to surf the Internet and play games.
A:had he failed he realized
B:he had failed he realized
C:he had failed did he realize
D:did he fail did he realize
B:he had failed he realized
C:he had failed did he realize
D:did he fail did he realize
正确答案是：
