that引导定语从句
that引导的定语从句，that作关系代词时可以修饰表示人或物的名词，作宾语时可以省略。that是定语从句中一个使用比较普遍的引导词，它可以等于who，whom，which。
The gril that is sitting under the tree is a good runner.
坐在树下的那个姑娘是很好的赛跑运动员。
She is the only person that solves this math probiem.
她是唯一能解开这道数学难题的人。
I\'d like to come on to that question later.
我想以后再讨论那个问题。
That is no way to treat another human being.
那绝不是对待他人的方式。