in front of
在...(范围外)的前面
There is a tree in front of the classroom.
in the front of
在...(范围内)的前面
There is a blackboard in the front of the classroom.
in front of
在...(范围外)的前面
There is a tree in front of the classroom.
in the front of
在...(范围内)的前面
There is a blackboard in the front of the classroom.