Cars play an important role in modem life, but they       also cause many problems like air pollution.
#87845
A
should
B
can
C
must
D
will
推荐题目
His failure in the exam suggested that he __________ the teacher’s instructions.
#89495
A
can’t have followed
B
needn’t have followed
C
mustn’t have followed
D
shouldn’t have followed
Without your help,we       this task.
#89666
A
don’t finish
B
will not finish
C
didn’t finish
D
would not have finished