As we all know, , the pollution will get worse and worse.A. not if carefully dealt withB. until not

【题目】As we all know, , the pollution will get worse and worse.

A. not if carefully dealt with

B. until not carefully dealt with

C. if not carefully dealt with

D. when not carefully dealt with

【答案】C

【解析】

试题分析：考查状语从句的省略。当before、if、when、until、unless等引导的状语从句主从句主语一致的时候，从句的主语可以省略，省略原则是当从句谓语中包含be动词时，可以省略从句主语和be动词，保留be之后的部分，被保留部分常为现在分词、不定式、过去分词 、形容词等。在此句中，完全结构是：if the pollution is not carefully dealt with，在省略之后应该选择C，否定词放在分词之前。