Every possible meansto prevent the air p
题型:选择题
问题:
Every possible means to prevent the air pollution, but the sky is not still clear.
A.is used
B.are used
C.has been used
D.have been used
Every possible means to prevent the air pollution, but the sky is not still clear.
A.is used
B.are used
C.has been used
D.have been used