It’s important us students carefully in class.A. for; listening B. of; listenC. for; to

问题补充：

It’s important us students carefully in class.

A. for; listening

B. of; listen

C. for; to listen

D. of; to listen

答案：

A. for; listening

B. of; listen

(答案→)C. for; to listen

D. of; to listen

解析：

试题分析:强调句式， It is adj for sb to do sth，做某事对某人来说怎么样。本句中it是形式主语，指代后面不定式内容做形式主语，句意：在课堂上认真听讲对学生们来说很重要。结合语境可知选C。