O字开头的单词或词组
ovaobservingolive oilopportuneoverrunon account ofoutreachoutliveoccupationalon saleoffice workeronomatopoeiaOkieoutflowon crediton-lineobtuseohon arrivalorchardorthopedicold schoolobbligatooustoligo-operationalotherwiseowe sth to sboutskirtson the horizonorder numberon the trackoveruseoff and onoverflewoverplayoil filterover the yearsonce and for alloff guardoutrightoverdose
