问题
选择题
There is still a long way to go to solve all the problems ______ conservation of natural resources.[ ]
A. concerning
B. concerned
C. concerning about
D. concerned about
答案
答案：A
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There is still a long way to go to solve all the problems ______ conservation of natural resources.[ ]
A. concerning
B. concerned
C. concerning about
D. concerned about
答案：A