Question

Please stop ________. Let's begin our class.

1. A.
   talk
2. B.
   to talk
3. C.
   talking
4. D.
   to talking

Answer 1

C
点拨：此题中stop有两种用法，即stop doing sth. 指停止正在进行的动作；stop to do sth. 表示停下来去做某事。由句意可知是停止正在做的事。