Every possible means ________ to prevent the air pollution，but the sky is still not very clear.
#85546
A
were using
B
have used
C
has been used
D
was used
推荐题目
—Ann asked me to remind you of the meeting this afternoon. Don’t forget it!—OK, I .
#43828
A
won’t
B
don’t
C
will
D
do
Taking a walk after supper _______ me _______fit.
#44055
A
help, keep
B
helps, keeps
C
help, keeps
D
helps, keep