O字開(kāi)頭的單詞或詞組
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