When the teacher came into the classroom the students .A. stop to talkB. stopped to talk

问题补充：

When the teacher came into the classroom, the students .

A. stop to talk

B. stopped to talk

C. stopped talking

D. stop talking

答案：

A. stop to talk

B. stopped to talk

(答案→)C. stopped talking

D. stop talking

解析：此题重点考查两个短语stop to do sth和stop doing sth的区别，前者表示停下来去做某事，后者表示停止做某事。根据语境可知此句的含义是当老师走进教室的时候，学生们都不讲话了，故选C。