O字开头的单词或词组
outreachohopportuneoctalold schoolOphidiaotorhinolaryngologyoccupationalordinateolive oiloffice workeroutliveonomatopoeiaon account ofoustovaoutflowoverflewobtuseorchardoutskirtsoperationalon creditOkieoverruleon arrivalorthopedicobbligatootherwiseoligo-overdoseon the horizonoveruseover the yearsowe sth to sborder numberoff and onon the trackoverplayoblongoutrightomnipotent
