#standard_cell  a primary cell used as a standard of electro-motive force
  supertype:  voltaic_cell__voltaiccell__galvaniccell__primary_cell__primarycell  an electric cell that generates an electromotive force by an irreversible conversion of chemical to electrical energy; cannot be recharged
  subtype:  Clark_cell__Clark_standard_cell  a form of voltaic cell once used as a standard for electromotive force
  subtype:  Weston_cell__cadmium_cell__cadmiumcell  a standard voltaic cell (trademark Weston)

No statement uses or specializes standard_cell; click here to add one.