A-A+
They have taken measures to solve the city’s p
问题详情
They have taken measures to solve the city’s pollution problem, but it may be some time ______the situation improves.
A．before
B．for
C．unless
D．since请帮忙给出正确答案和分析，谢谢！
参考答案
正确答案：A
解析：他们已采取措施解决城市污染问题，但要使情况好转，还需要一段时间。It may／will be some time before…意为“要…还需要等一段时间”。
