—May I smoke here ?—If you ____, choose a seat in the smoking section. 
#90273
A
should
B
could
C
may
D
must
推荐题目
—Sorry, the tickets have already been sold out.—Really? Maybe I _______ a little earlier.
#86439
A
should come
B
should have come
C
could have come
D
must have come
You_____make such mistakes again.
#88888
A
should never
B
should not always
C
would always not
D
would not forever
 He directed exposure to pigs,otherwise he_______pig flu.
#90450
A
couldn’t get
B
wouldn’t have gotten
C
couldn’t have got
D
woud get