which引导的非限制性定语从句
问题描述：
which引导的非限制性定语从句
The building,in front of which sat a boy,was a school
但是不是说 which 引导的定语从句只能位于主句后吗?那这句话怎么插在中间了?
答
In front of which sat a boy 作定语修饰the building