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
mean单数复数一个形式。在本题中代表单数。
练习册系列答案
相关题目
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
mean单数复数一个形式。在本题中代表单数。