Nobody knows for sure how dinosaurs died out 65,000,000 years ago. It _______ because of sudden changes of their living conditions.
#62591
A
must have happened
B
would have happened
C
should have happened
D
might have happened
推荐题目
—We want someone to design the new art museum for us?— the young fellow have a try?
#63256
A
May
B
Shall
C
Will
D
Need
—Listen! Is that Pingping playing the guitar? —No. It __________be Pingping. He has gone to Beijing.
#76611
A
mustn’t
B
may
C
can’t
D
must
(2013·四川省都江堰市二模)—Mike, I can't find my watch anywhere.—You ________ it while working out.
#62422
A
may have lost
B
could have lost
C
would have lost
D
should have lost
—Can you keep a secret?—You ________ worry—I'm not going to mention it to anyone.
#62328
A
needn't
B
couldn't
C
mustn't
D
won't
------Is this ruler Mary’s?------No, it _______Mary’s. Hers is on the desk..
#76705
A
can be
B
can’t be
C
must be
D
mustn’t be