O字开头的单词或词组
onwardoverhaulotterone-offomeletoutspokenobstructoneselfoverloadOkieoversleeponomatopoeiaoverleafOceaniaoverjoyedoff and onoverdoOrizaba jalapopportuneovoobbligatoOOPoff-siteoverreactoffice workerorchidowe sth to sboverestimateoff guardoverrunoil filteron the horizonorchardobservingoilson the trackOrpheusofficiallyoverwhelminglyoligo-out of serviceoutlive
