--Is your friend quiet?--No he never stops .A. talkB. talkingC. to talkD. is talking

问题补充：

--Is your friend quiet?

--No, he never stops .

A. talk

B. talking

C. to talk

D. is talking

答案：

A. talk

(答案→)B. talking

C. to talk

D. is talking

解析：本题的含义为你的朋友文静吗？不，他总是说个不停，stop doing sth表示停止做某事的含义，故本题选B。