The man who is standing in front of the school library is the headmaster.
=The man standing in front of the school library is the headmaster.
站在校图书馆前面的那个人是校长
The man who is standing in front of the school library is the headmaster.
=The man standing in front of the school library is the headmaster.
站在校图书馆前面的那个人是校长