为什么这两个介词可以在一起使用from withinFirst year units from within the BA schedule

问题描述:

为什么这两个介词可以在一起使用from within
First year units from within the BA schedule

from后面经常接介词的,是英语中介词接介词的特例,又如:
A scream was heard from inside the room.房间里传来尖叫声.