I advise you to give up smoking for it is to your health.A. harmB. harmlessC. harmfulD. ha

问题补充：

I advise you to give up smoking for it is to your health.

A. harm

B. harmless

C. harmful

D. harmfully

答案：

A. harm

B. harmless

(答案→)C. harmful

D. harmfully

解析：考查短语：be harmful to 对什么有害，句意：我建议你戒烟因为吸烟对你的健康有害。所以选C。