(1) A member of a district board or local board, when appointed by virtue of an office, shall, unless and until the Local Government otherwise directs, continue to b e a member of the board while he continues to hold that office.
     (2) The term of office of all other elected and appointed members respectively of a district board or local board shall be fixed by the Local Government by rules made under this Act, and may be so fixed as to provide for the retirement of members by rotation, but shall not exceed three years.
     (3) An outgoing member shall, if otherwise qualified, be again eligible for election or appointment.