This problem may lead to more serious ones if unsolved.A. makingB. leftC. remainedD. keep

问题补充：

This problem may lead to more serious ones if unsolved.

A. making

B. left

C. remained

D. keeping

答案：

A. making

(答案→)B. left

C. remained

D. keeping

解析： 考查状语从句的省略。Leave something +done 。题意 如果这个问题不解决的话，会导致严重的问题。

考点 状语从句省略。