Every possible means ______ to prevent the air pollution, but the sky is still not clear.
#85598
A
has been used
B
have been used
C
is used
D
are used
推荐题目
Physics ________ my favorite subject. I like it so much that I wish we had a physics class every day.
#85752
A
is
B
are
C
was
D
have been
---- _____either you or he to go there? ---- _____is.
#86286
A
Are; Both
B
Are; Neither
C
Is; Neither
D
Is; Each