The problem is so difficult that few students can solve them.
问题描述：
The problem is so difficult that few students can solve them.
这句话有没有语病?我觉得应该用
The problems is so difficult that few students can solve them.
或者
The problem is so difficult that few students can solve it.
到底怎么样才对
答
第一句对,因为problems 是复数,故要用them 代替The problem is so difficult that few students can solve them.
对吗？不对，要把them 改为it
因为这里的problem 是单数
sorry, 刚开始没注意看，你开始提的两个句子都是对的（ 只是他们的主语一个是复数‘ 这些问题’，一个是单数‘ 这个问题’
The problems is so difficult that few students can solve them.
或者
The problem is so difficult that few students can solve it.