Every possible means ______ to prevent the air pollution, but the sky is still not clear.
#86302
A
is used
B
are used
C
has been used
D
have been used
推荐题目
The number of people invited ____ fifty, but a number of them ___ absent for different reason.
#85769
A
were; was
B
was; was
C
were; were
D
was; were
--There ____ lots of information on sports on ESPN.com．--But most of it is in English．
#43893
A
has
B
have
C
are
D
is