Mary _______ her mother with the housework, but she didn’t.  
#63072
A
must have helped
B
ought to have helped
C
must help
D
should help
推荐题目
 My sister met him at the street yesterday afternoon, so he __________ your lecture.
#63076
A
shouldn’t have attended
B
needn’t have attended
C
mustn’t have attended
D
couldn’t have attended
People who drink wine ______ to drive after May Day. 
#77648
A
don’t allow
B
isn’t allowed
C
mustn’t allow
D
mustn’t be allowed