single representative single request single resident single resolution single resolution board single resolution mechanism single resource single response single restaurant single result single review single ride single rider single right single ring single risk single road single rock single role single roll single roller single roof single room single room double room single room with shared single rooms single root single rope single rose single rotation single rotor single round single round-robin single route single row single rule single run single runway single russian single safety single sale single sales single sample single satellite single scan single scene single school single scratch single screen single screw single screw extruder single scull single sculls single search single season single seat single seater single second single section single sector single security single seed single segment single selection single seniors single sensor single sentence single sequence single series single serve single server single service single serving single session single set single sex single shaft single share single shared single shareholder single sheet single sheet of paper single sheets single shell single shift single ship single shooter single shot single shots single shoulder single show single shred single side single sideband single sided single sign single sign-on single signal single simple