—Mary’s score on the test is the highest in her class.—Really? She     have studied very hard.
#87447
A
may
B
ought to
C
must
D
should
推荐题目
More and more people have come to realize that if we had taken effective measures much earlier, the air quality ______ so seriously now. 
#86958
A
is not polluted
B
would not be polluted
C
had not been polluted
D
would not have been polluted
 --- I saw your uncle take a taxi to the airport. Why didn’t you drive him there? --- I ______. But my car ______.
#86778
A
would; was fixed
B
would have; was fixed
C
would have; was being fixed
D
did; was being fixed
- Has John arrived yet?   -- No, she _______ an hour ago.
#88137
A
was supposed to come
B
must have come
C
should come
D
ought to have come