Teachers’ job is the students learn well.A. helpingB. helpC. to helpD. helped

问题补充：

Teachers’ job is the students learn well.

A. helping

B. help

C. to help

D. helped

答案：

A. helping

B. help

(答案→)C. to help

D. helped

解析：句意：老师们的工作是帮助学生们学好。根据题意可知本句不是现在进行时态也不是被动语态，be动词也不能和原形动词连用，故选C，不定式短语做表语。