For a position that is normally held at one time by one person only, can it be used with "the" article?<br/><br/>for example:<br/><br/>1. Mr banerji became (the) headteacher of the high school in 1995.<br/><br/>2. <font color="#808080">Ed Koch was for many years (the) mayor of New York.</font><br/><br/><font color="#808080"></font><br/><br/><font color="#808080">This really confuses me and beats my brain.</font>