It is not right in public places. A. smokesB. smokingC. smokedD. to smoke

问题补充：

It is not right in public places.

A. smokes

B. smoking

C. smoked

D. to smoke

答案：

A. smokes

B. smoking

C. smoked

(答案→)D. to smoke

解析：本题中的it是形式主语，真正主语应写在句尾用动词不定式to do，故本题选D。