There are some health problems that when in time can become bigger ones later on.A. no

问题补充：

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

答案：

(答案→)A. not treated

B. not being treated

C. not to be treated

D. not having been treated

解析：考查状语从句的省略句：句意：有很多健康问题，如果得不到及时处理的话可能会变得很糟糕。此处非谓语动词做条件状语，其逻辑主语是health problems，被动关系，一般式，相当于when they are not treated in time。当主从句的主语一致的时候，可以省略从句的主语和be动词。选A。