Although this medicine can cure you your illness it has a bad effect you.A. for；in B. for；

问题补充：

Although this medicine can cure you your illness，it has a bad effect you.

A. for；in

B. for；on

C. of；on

D. of；at

答案：

A. for；in

B. for；on

(答案→)C. of；on

D. of；at

解析：考查固定搭配。固定搭配Cure sb of sth治愈某人…病；have an effect on…对…有影响；句意：尽管这种药能够治愈你的病，它对于你也有负面的影响。故C正确。