O字开头的单词或词组
operating systemorchestrateon guardornamentover-the-counteron-the-joboutgrownopusOmanobliviousorientalon and offorthodoxone after anotherOct.overtureovertoutbreakoccultopposedobsidianoverheardohoorphanageOxfordourson dutyonceoff-limitsotorhinolaryngologyocteton arrivaloutdoorsoutcomeOklahomaotteroverchargeOphidiaobjectivenessoverhaulonyxone-off
