O字开头的单词或词组
operableoustobjectionoil pump purifierOPonuson one's toesoutskirton endon scheduleon-lineold schoolon earthorthopedicover the yearsopen-airobsceneoblongoverwriteoutlieroverdueopossumosteo-official languageopen seaoccupationaloversideoverthrownOlympusOedipusonwardson topobviateobservatoryowlout of controlon the way tooverthrowonce a weekof lateoverworkon the move
