O字开头的单词或词组
oscillationOsirisozone layeron the airorganizationaloil spilloverrateordainoperation manualovercameos1out of boundsoakumOSFother oneoff-peakO2octa-once or twiceopen onoliooffenceon the declineon the alertoverdraworal examinationoscoverflyoutshineoverboardorder formoutstretchoperandoff the cuffobjectivityone-eyedopt foroverflewover weightorthonormaloppositelyOLE
