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
The father as well as his three children _______ skating on the frozen river every Sunday afternoon in winter.
#85739
A
is going
B
go
C
goes
D
are going
Listening to loud music at rock concerts _____ caused hearing loss in some teenagers.
#85680
A
is
B
are
C
has
D
have
I think that ____ very difficult to learn.
#86022
A
the politics is
B
politics is
C
politics are
D
the politics are
The number of tigers in Asia________ getting smaller and smaller and a large number of people_________ trying to protect them．
#43555
A
are；are
B
is；is
C
is；are
D
are；is