问题

had taken such effective measures much earlier,the river ________ so seriously now.

A:is notpolluted
B:would not be polluted
C:had not beenpolluted
D:would not have been polluted

正确答案是：

同类题型

Where do you live— In Beijing. It is one of in China.

Not only_______know the theory, but also_______learn how to apply it in practice.

That little boy preferred ________ out to play ratherthan ________ TV at home.

Recently quite a lot of experts havesuggested that another law on wildlife protectionas soon as possible．

It was ____ to see so many ____ people in a smalltown