Where is the library?-----It's______the teaching bhilding.A.in front of B.behind of
问题描述：
Where is the library?-----It's______the teaching bhilding.A.in front of B.behind of
答
A behind不加of为什么？behind在...后面behind表示“在后面”behind of 表示“在...的后面”behind既可以作副词 意思是 在后面 也可以做介词 在...的后面 没有behind of