问题补充:
As we all know, smoking people’s health.
A. is harmful to
B. do harm fo
C. does harmful to
D. harm
答案:
(答案→)A. is harmful to
B. do harm fo
C. does harmful to
D. harm
解析:考查词组和主谓一致:对…有害:be harmful to或do harm to或用harm sth,所以先排除C项,当主语是动名词的时候,谓语是单数,选A。