O字开头的单词或词组
orangeonly ifon purposeourorgyoopsone by oneovercomeoralon behalf ofopposeorganizedoutgoingoutstandingoccasionallyodeomicronoutlastoverwhelmingobligateoutweighonlyone anotheron-siteoptimisticovaloforacleon the spotoptimizeoccasionon no accountowe toon demandoafoutoutlineoriginallyonce againoutfitobeseof oneself
