<prompt> Translate the following text to EnglishMashirika hayo yasiyo rasmi huchagua washiriki kwa nasibu ili warudi nyumbani kwa vipindi vya utumishi - kufanya kazi kama meya wa kujitolea, kwa mfano, au karani wa mji.  <response>: The informal associations select members at random to return home for periods of service - working as a volunteer mayor, for example, or town clerk. 