the doctor has two children, .are teachers.

问题描述:

the doctor has two children, .are teachers.
为什么不能用both of them ,而用both of the children?

我觉得这两者在语法上没什么区别,如果说both of them不对的话,也应该改为both of which,因为两句中间是逗号,不能单纯把两个完整的句子并列,只能采取从句的形式.