Now the air in Yancheng is than it used to be. Something must be done to stop it.A. very g

问题补充：

Now the air in Yancheng is than it used to be. Something must be done to stop it.

A. very good

B. much better

C. rather bad

D. even worse

答案：

A. very good

B. much better

C. rather bad

(答案→)D. even worse

解析：句意：现在盐城的空气比过去更差了。必须采取措施阻止它。A. very good非常好； B. much better更好； C. rather bad相当差； D.even worse更差。根据than，此处用比较级，故排除AC两项。根据Something must be done to stop it.可知要阻止它，因此知道盐城的天气是更差了，故选D。