英语In my opinion that students help each other with their lessons

题目

英语In my opinion that students help each other with their lessons
In my opinion ,that students help each other with their lessons_______ not only to their teachers but also to themselves.
a.are helpful b.helps c.is a help d.is help
为什么

答案

首先,In my opinion 后面 的那个逗号 最好不要管它,其实是连一起的
其次,that students help each other with their lessons 作为一个整体充当主语,所以用is
然后,a help to somebody 是固定搭配
因此,这道题目的答案应该是c