Please stop .It’s time for class.A. to talkB. talkC. talkingD. speaking

问题补充：

Please stop .It’s time for class.

A. to talk

B. talk

C. talking

D. speaking

答案：

A. to talk

B. talk

(答案→)C. talking

D. speaking

解析：stop to do sth 表示停下去做另一件事，stop doing sth 表示停下做原来的事。