The pollution problem here seems to get more and more serious.----Yes.Somethine___about it.
问题描述:
The pollution problem here seems to get more and more serious.----Yes.Somethine___about it.
A has done
B must be done
C is doing
D was done
回答并给我简单的讲讲.
答
B must be done
一定要采取措施