一个句子只能有一个谓语动词,请问这个句子怎么修改呢?

题目

一个句子只能有一个谓语动词,请问这个句子怎么修改呢?
In the past,students had to bring a huge bag of books to classrooms,listened to the teacher,read paper materials and discuss together after class

答案

这句有错吧,分词作状语在这里翻不通,所以我觉得这只不过是几个并列的句子
In the past,students had to bring a huge bag of books to classrooms,listen to the teacher,read paper materials and discuss together after class.
如果不省略的话,应该是这样的:
In the past,students had to bring a huge bag of books to classrooms.They had to listen to the teacher.They had to read paper materials and discuss together after class.