题目内容
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
【答案】
C
【解析】略
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题目内容
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
C
【解析】略