oarfish n. 皇带鱼
oasis n.(沙漠中的)绿洲
oast n. 啤酒花烘炉
oat n. 燕麦，麦片粥
oaten a. 燕麦的，麦杆制的
oath n.誓言，誓约，宣誓
oatmeal n. 燕麦片，燕麦粥
obduracy n. 顽固，执拗，冷酷
obdurate adj. 固执的，顽固的。
obedience n.服从，顺从；管辖
obedient n.服从的，顺从的
obeisance n. 鞠躬，敬礼
obelisk n. 方尖石塔，短剑号，疑问记号
obese adj. 极肥胖的
She heard the sound of breaking glass, followed by a muttered oath.
她听到打碎玻璃的'响声，接着是低声的咒骂。
Barons had to swear an oath of allegiance to the king.
贵族须宣誓效忠国王。
Three officers gave evidence on oath against him.
3位警官经宣誓提出了对他不利的证据。
His girlfriend had gone into the witness box and taken the oath
他的女朋友进入证人席并立了誓。
The constitution requires members of parliament to take an oath of allegiance
宪法规定，议员必须宣誓效忠。