问题

Every possible means _______ to prevent the air pollution, but the sky is still not clear.[ ]

A: is used
B: are used
C: has been used
D: have been used

正确答案是：

同类题型

Tim is in good shape physically_______ he doesn’t get much exercise

下列各句中，加点的成语使用正确的一项是

ust have finished the work by the endof last month, ______

－Where’s the zoo Is it far away from our school－No. It’s ______ north of our school, about three kilometers _______.

ving standard of the people in China, _______ is shown in the report, has improved over the past decades.