O字开头的单词或词组
organismoverseasoysteroutsiderorienton boardoriginalityoathone-pieceold-fashionedon the sceneostrichover and over againout of dateongoingold and youngon occasionoptimismoasisoakobtainingonce in a whileOscarover timeon the sideodoron one's ownother thanoverlapoverviewon the walloptionalOsakaon handoutdooroverlookorientationor soordersobstinateobservationordered
