in front of, in the front of
  in front of的意思是“在……前面”。
  如:
  There is a tree in front of the house.
  房子前面有一棵树。
  in the front of的意思是“在……前部”,指在某个空间范围内的前面。如:
  There is a blackboard in the front of the classroom.
  教室里前部有一块黑板。