Every possible means _____ to prevent the air pollution, but the sky is still not clear.
#85634
A
is used
B
are used
C
has been used
D
have been used
推荐题目
---I saw Betty to Grandpa Li's home just now.---Yes. She’s often seen _________ the old man with the housework.
#43823
A
go, help
B
going, to help
C
go, to help
D
going, helps
Robert with his two kids ________ to the beach for vacation every year.
#44177
A
go
B
went
C
are going
D
goes
A poet and artist going to speak tomorrow afternoon to us about Chinese literature.
#85923
A
is
B
are
C
was
D
were