问题

More and more people have come to realize that if we had taken effective measures much earlier, the air quality ______ so seriously now.

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

正确答案是：

同类题型

We had a marvelous holiday: only the lasttwo days were slightly _____ by the weather.

My parents told me _______ lies（谎言）.

Many in the company doubted whether the new product could bring in ____ those sold

There is such a problem _________ we allshould _________.

_______ advice my teacher gave me ! It has helped me a lot.