O字开头的单词或词组
operableoriginal characteroutlieroustonusobjectionon one's toesoil pump purifieroverwriteoutskirton scheduleon-lineon earthold schoolon endobsceneoblongowlorthopedicover the yearsOlympusopen-airosteo-overdueopen seaopossumofficial languageOedipusoccupationalonwardsoversideoverthrownobservatoryon topobviateoverthrowOdinout of controlonce a weekof lateoverjoyon the move
