Question

【题目】There are some health problems that, when ________ in time, can become bigger ones later on.

A. not treated

B. not being treated

C. not to be treated

D. not having been treated

Answer 1

【答案】A

【解析】此处是状语从句的省略形式，补充完整应为：when they are not treatedin time. 从句主语与主句主语一致，且从句中含有be的形式，可以将从句中的主语与be动词同时省略，只保留not treated形式，因此A项正确。