pollution has become a worldwide problem,it may be many years ( )the situation improves

分类: 作业答案 • 2023-01-13 21:21:46

问题描述：

pollution has become a worldwide problem,it may be many years ( )the situation improves
A.after B.before C.as D.since
为什么

答

B
因为逻辑上就是before.其余选项根本不足为虑.