One thing’s for sure, the fire _____by some cigarette butts.
#88084
A
might cause
B
could have caused
C
must have been caused
D
should be caused
推荐题目
－Why didn’t Susan come to see us yesterday as she promised?－______.
#87312
A
She must be busy
B
She might have been free
C
She must have been busy
D
She can’t be free
He ________ get into his own house because he has lost his keys.
#88359
A
mustn’t
B
doesn’t have to
C
can’t
D
needn’t
—You didn't wait for Mr. Smith last night, did you?—Yes, but we ________. He didn't return home at all.
#87275
A
don't have to
B
needn't have
C
didn't need to
D
should have
Look at the clock! It's time ______ work.
#90300
A
we started
B
we'll start
C
we're starting
D
we have started
If you_______ my advice last month, you wouldn’t have lost his job．
#87066
A
followed
B
should follow
C
had followed
D
would follow