The problem is very difficult .You must think about it careful.这个句子错在哪里?

问题描述:

The problem is very difficult .You must think about it careful.这个句子错在哪里?
可能错的地方在A .is B difficult.C .think about D .careful
为什么列?请说明原因

D错.应为carefully,因为要用adv.(副词)来修饰v.(动词或动词词组).句子修该后应为:You must think about it carefully.此处carefully用来修饰think about.