Now the air in our hometown is than it was before. Something must be done.A. much betterB

问题补充：

Now the air in our hometown is than it was before. Something must be done.

A. much better

B. more worse

C. more better

D. much worse

答案：

A. much better

B. more worse

C. more better

(答案→)D. much worse

解析：根据Something must be done“一些事必须被做”可知，我们的空气并不好，所以应该用worse；又因为worse本身就是比较级，不需要加more，但much可放在比较级前面，表示“多得多”。故本题选D .