§ 2101. Officers  of  district. 1. Each common school district shall  have one or three trustees  as  the  district  determines,  a  collector  except  in  first class towns and except as may be otherwise provided by  law, and if the district so decides a treasurer. 2. Each union free school district shall have  a  board  of  education  consisting  of  from  three  to  nine  trustees  as  the  district shall  determine.