白头翁治疗热毒血痢，是取其什么功效（）

A.清热燥湿

B.止血

C.清热解毒

D.利湿浊

E.凉血止痢

The heavy smoker has decided to _____ smoking, for he knows smoking _____ his health.

A．cut down, is harmful to

B．cut up, does harm to

C．cut off, is harmful for

D．cut down, does harm for