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
--- Whose hair band is this ? ________ it be Kate’s ? --- I’m not sure . It ________ be hers.
#75310
A
May ; must
B
Must ; may
C
Can ; must
D
Can ; may
—What do you think of Peter?—He ______ be really difficult to get along with even though he’s a nice person in general.
#62783
A
shall
B
should
C
must
D
can
I’m feeling much better now so you ______ call the doctor.
#78333
A
couldn’t
B
wouldn’t
C
can’t
D
needn’t
-Was the United State of America founded on July 4th, 1776？ --You _________ be right but I need to check it in the history textbook anyway.
#62356
A
have to
B
must
C
may
D
will
— _______ do you go shopping with your mother?— I seldom do that.
#77640
A
How often
B
How soon
C
How far
D
How much