n. 接待日，可参观的日子；

n. 发源，起始，鼻；

n. 零头，碎屑，碎屑( oddment的名词复数 )，余料，附页；

[例句] ...searching street markets for interesting jewellery and oddments.

n. 乳白光，蛋白色光，乳光；

[例句] Elaine turned her opalescent eyes on him.

[例句] ...a sky which was still faintly opalescent.

n. 出身( origin的名词复数 )，起点，由来，[解剖学]1)。 由来；

[例句] ...theories about the origin of life...

[例句] The disorder in military policy had its origins in Truman's first term...

n. 省略( omission的名词复数 )，删节，遗漏，略去或漏掉的事（或人）；

[例句] The duke was surprised by his wife's omission from the guest list.

[例句] ...the prosecution's seemingly malicious omission of recorded evidence.

n. （房屋等的）居住者，占有人( occupant的名词复数 )；

[例句] Most of the occupants had left before the fire broke out...

[例句] The filing cabinets had all gone with the previous occupants.

v. （使某物）氧化，（使某物）生锈( oxidize的过去式和过去分词 )；

[例句] Aluminium is rapidly oxidized in air...

[例句] The original white lead pigments have oxidized and turned black.

v. 省略( omit的过去式和过去分词 )，遗漏，删掉，忘记做；

[例句] Omit the salt in this recipe...

[例句] Our apologies to David Pannick for omitting his name from last week's article.

n. 旁观者，观看者( onlooker的名词复数 )；

[例句] A handful of onlookers stand in the field watching.

adj. （城市等）人口过密[过多]的；

[例句] Environmentalists say Australia is already overpopulated.

[例句] ...the overpopulated valleys of the north Omagh region.

v. 数量多于，比…多( outnumber的过去式和过去分词 )；

[例句] ...a town where men outnumber women four to one...

[例句] Donkeys outnumber cars in this landscape of tiny stonewalled fields.

n. 牡蛎( oyster的名词复数 )；

[例句] He had two dozen oysters and enjoyed every one of them.

[例句] You're young, you've got a lot of opportunity. The world is your oyster.

v. 胜过( outdo的过去分词 )；

[例句] It was important for me to outdo them, to feel better than they were...

[例句] Both sides have tried to outdo each other to show how tough they can be.

n. 歹徒，亡命之徒( outlaw的名词复数 )，逃犯；

[例句] In 1975 gambling was outlawed...

[例句] The German government has outlawed some fascist groups.

v. 服从，听从( obey的现在分词 )，遵守，遵循；

[例句] Cissie obeyed her mother without question...

[例句] Most people obey the law...

n. 发生( occurrence的名词复数 )，出现，事件，发生的事；

[例句] Complaints seemed to be an everyday occurrence...

[例句] The food queues have become a daily occurrence across the country.

n. 烤箱，炉( oven的名词复数 )；

[例句] Put the onions and ginger in the oven and let them roast for thirty minutes.

n. 开端( offset的名词复数 )，出发；v. 抵消( offset的第三人称单数 )，补偿，（为了比较的目的而）把…并列（或并置），为（管道等）装支管；

[例句] The increase in pay costs was more than offset by higher productivity...

[例句] The move is designed to help offset the shortfall in world oil supplies caused by the UN embargo.

v. 起源于，来自，产生( originate的第三人称单数 )，创造，创始，开创；

[例句] The disease originated in Africa...

[例句] All carbohydrates originate from plants...