It will be many years the doctors and medical scientists can find for cancer.A. since; c

问题补充：

It will be many years the doctors and medical scientists can find for cancer.

A. since; cures

B. when; treatments

C. before; cures

D. until; treaments

答案：

A. since; cures

B. when; treatments

(答案→)C. before; cures

D. until; treaments

解析：第一空考查连词，since 自从，when 当什么的时候，before 在什么之前，才，就，until直到，第二空考查短语：cures for cancer癌症的治疗方法，句意：许多年医生们和医疗科学家才找到了癌症的治疗方法。所以选C。