问题

It was _______ back home after the experiment.
A:had I gotwhen
B:untilmidnight that he didn’t go
C:not untilmidnight that he went
D:untilmidnight when he didn’t go
B:untilmidnight that he didn’t go
C:not untilmidnight that he went
D:untilmidnight when he didn’t go
正确答案是: