问题补充:
When the teacher came into the classroom, we all stopped.
A. to talk
B. talk
C. talking
D. talked
答案:
A. to talk
B. talk
(答案→)C. talking
D. talked
解析:句意:当老师走进教室的时候,我们都停止说话。Stop doing sth,停止做某事,停下手头正在做的事情;stop to do sth.停下来去做某事,不定式表示将要去做的事情;故选C。