问题补充:
—You shouldn’t have shouted at your mother. It really hurt her.
—Exactly. I crazy at the time.
A. must be
B. could be
C. must have been
D. could have been
答案:
A. must be
B. could be
(答案→)C. must have been
D. could have been
解析:句意:--你不应该对你妈妈大声说话的。这真的伤害了她。--确实是,我那时一定是发疯了。从shouldn’t have done说明是过去的事情,所以排除AB,must have done是对过去情况的肯定推测,could have done是“过去本可能做却没做“,不符合句意。选C。