All possible means ____ to prevent the air pollution, but the sky is still not clear.
#100326
A
is used
B
has been used
C
are use
D
have been used
推荐题目
Our English teacher , having explained to us how to design a project, allowed us a whole week’s preparation and then ______the class.
#100386
A
to dismiss
B
dismissed
C
dismissing
D
having dismissed
Hurry up！Mark and Carol ________ us. (2013·北京，28)
#99436
A
expect
B
are expecting
C
have expected
D
will expect
—Hi, Jack! When did you arrive in Berlin?—Last weekend .I a different culture since then.
#101417
A
was experiencing
B
will be experiencing
C
have been experiencing
D
had been experiencing
Proper first aid can save a seriously injured person，especially when he or she is bleeding heavily or______.
#104358
A
has poisoned
B
was poisoned
C
has been poisoned
D
is poisoning
—How did you find Nike’s singing last night.—To be honest, his singing didn’t to me.
#100825
A
appeal
B
belong
C
refer
D
occur