There is no light in the room. They must have gone to the lecture. ?
A. didn’t they
B. haven’t they
C. don’t they
D. mustn’t they
网友回答
A. didn’t they
(答案→)B. haven’t they
C. don’t they
D. mustn’t they
解析： 本题是一个反义疑问句，前句是肯定的句子，后句应该用否定的结构+人称，前句的助动词是have，故用其否定形式haven’t，故本题选B。