ocean acidification
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C1 noun ˈoʊʃən əˌsɪdɪfɪˈkeɪʃən

ocean acidification

海洋酸化
Meaning
The ongoing decrease in the pH of the Earth's oceans, caused by the absorption of carbon dioxide from the atmosphere.
Example
Ocean acidification is caused by atmospheric CO2 absorption.
海洋酸化是由大气中CO2的吸收引起的。
B2 verb /ˌoʊvərˈwɛlm/

overwhelm

Meaning
to overpower someone emotionally or physically; to be too much to handle
Example
She was overwhelmed with gratitude after receiving the help.
B2 noun /ˈoʊ.vər ɡroʊθ/

Over growth

过度生长
Meaning
excessive growth beyond normal size; too much development or expansion
Example
The overgrowth of weeds made the garden look untidy.
杂草的过度生长让花园显得不整洁。
B2 noun /ˈɒpəreɪtər/

operator

操作员
Meaning
a person who operates equipment, a business, or controls something
Example
The machine operator ensured that everything ran smoothly.
机器操作员确保一切顺利运行。
B2 noun /ˈɒs.trɪtʃ/

Ostrich

鸵鸟
Meaning
a large flightless bird native to Africa with long legs and neck
Example
The ostrich is the world's largest bird.
鸵鸟是世界上最大的鸟。
C2 verb /ˌoʊvərˈstraɪd/

overstride

跨越大步走
Meaning
To stride over something; to step across with long steps.
Example
He managed to overstride the narrow stream with ease.
他轻松地跨越了狭窄的溪流。
C2 adjective /əˈfɪʃəs/

officious

多管闲事
Meaning
Excessively eager to offer unwanted help or advice; meddlesome.
Example
The officious guard kept interrupting the visitors with unnecessary instructions.
那位多管闲事的警卫不断用不必要的指令打扰游客。
B2 noun /ˈaʊtˌsɛt/

outset

开始
Meaning
the beginning or start of something
Example
From the outset, the project seemed ambitious but achievable.
从一开始，项目看起来雄心勃勃但可以实现。
C2 adjective /ˌoʊvərˈwiːnɪŋ/

overweening

过度自负
Meaning
excessively arrogant or prideful
Example
His overweening pride cost him many friends.
他过度的自豪让他失去了许多朋友。
B2 noun /ɑːks/

Ox

牛
Meaning
a large strong animal used for pulling heavy loads or plowing fields
Example
The farmer used an ox to plow the field.
农民用牛耕地。
A1 adjective /ˈʌðər/

other

其他
Meaning
used to refer to something different from the one already mentioned or known
Example
I don't want this one, I will take the other one.
我不想要这个，我会拿另一个。
C1 noun /əbˈdʒɛktər/

objector

反对者
Meaning
a person who expresses opposition or disapproval to something
Example
The objector raised his concerns during the town meeting.
反对者在市议会会议中表达了他的关切。
C1 noun /ˈoʊvərˌtʊr/

overture

序曲 / 提议
Meaning
An introduction to something more substantial; a proposal or preliminary action.
Example
The peace overture was welcomed by both nations.
和平提议得到了两个国家的欢迎。
C2 noun /ˌɒstɛnˈteɪʃən/

ostentation

炫耀
Meaning
excessive display of wealth or knowledge intended to attract admiration or envy
Example
The billionaire’s party was full of ostentation and luxury.
亿万富翁的派对充满了炫耀和奢华。
C1 verb /ˌoʊvərˈrʌn/

overrun

侵占
Meaning
to spread over or occupy completely; to exceed a limit or time
Example
The garden was overrun with weeds.
花园被杂草淹没。
B1 verb /oʊ/

owe

欠债
Meaning
to be under obligation to pay or repay; to be indebted
Example
I owe my success to my parents' support.
我将我的成功归功于父母的支持。
C1 noun /ˈɔːrkɪd/

Orchid

兰花
Meaning
a diverse family of flowering plants known for their exotic and often fragrant flowers
Example
The white orchid on the windowsill bloomed for months.
窗台上的白色兰花开了好几个月。
B2 adjective /aʊtˈreɪdʒəs/

outrageous

骇人听闻
Meaning
Shockingly bad or excessive; very unusual or amusing.
Example
The comedian told an outrageous joke.
这位喜剧演员讲了一个骇人听闻的笑话。
B2 noun /ˈɔːɡənɪzəm/

organism

有机体
Meaning
a living thing that has an organized structure and can grow and reproduce
Example
Every organism needs water to survive.
每个有机体都需要水才能生存。
C2 adjective /ɑːlˈfæktəri/

olfactory

Meaning
Relating to the sense of smell.
Example
The perfume activated her olfactory nerves immediately.
B1 verb /ˈɔːrɡənaɪz/

organize

组织
Meaning
to arrange systematically; to plan and coordinate
Example
She organized a surprise party for her friend.
她为她的朋友组织了一个惊喜派对。
C1 adjective /ɒˈstɛnsəbl/

ostensible

表面上
Meaning
stated or appearing to be true, but not necessarily so
Example
His ostensible reason for leaving was illness, but many doubted it.
他离开的表面上原因是生病，但许多人对此表示怀疑。
B2 verb /əˈblaɪdʒ/

oblige

迫使
Meaning
to compel or require someone to do something; to help or do a favor
Example
I would be happy to oblige you with the information you need.
我很乐意为你提供所需的信息。
C1 adjective /ˈaʊt.kɑːst/

Outcast

被排斥的人
Meaning
rejected by society; excluded person
Example
He felt like an outcast in his new school.
他在新学校里感觉自己像一个被排斥的人。
B2 verb /ˈɒkjʊpaɪ/

occupy

占据
Meaning
to take up space or time; to live or work in a place
Example
The new family will occupy the house next month.
新家庭将于下个月入住这所房子。
B2 noun /ˈɔːkɪstrə/

orchestra

管弦乐队
Meaning
a large group of musicians playing different instruments together
Example
The orchestra performed beautifully at the concert.
管弦乐队在音乐会上演奏得非常出色。
B1 verb /ˈɒpəreɪt/

operate

操作
Meaning
to function; to control or manage; to perform surgery
Example
The surgeon will operate on the patient tomorrow.
外科医生明天将为病人做手术。
C1 noun /ˌəʊvərɪksˌplɔɪˈteɪʃən/

overexploitation

过度开发
Meaning
The unsustainable use of natural resources at a rate that exceeds their ability to regenerate, leading to depletion and environmental degradation.
Example
Overexploitation of natural resources leads to environmental degradation.
过度开发自然资源会导致环境退化。
B1 noun /ˈɔːfɪsər/

officer

警官
Meaning
a person in a position of authority, especially in law enforcement
Example
The officer gave him a ticket for speeding.
警官因超速给了他一张罚单。
B2 noun /ˈaʊtɪŋ/

outing

短途旅行
Meaning
a short trip or excursion, often for leisure or enjoyment
Example
They had a lovely outing at the beach last weekend.
他们上周末在海滩上度过了一个美好的短途旅行。
B2 adjective /ˈɒnɡəʊɪŋ/

ongoing

进行中
Meaning
continuing; still in progress
Example
The ongoing project will finish next month.
进行中的项目将在下个月完成。
A2 noun /ˈɒm.lət/

Omelet

煎蛋饼
Meaning
a dish made from beaten eggs cooked in a frying pan and often folded around a filling
Example
She made a cheese omelet for breakfast.
她做了一个奶酪煎蛋饼作为早餐。
C2 noun /ˈoʊ.vər.let/

Overlet

床垫
Meaning
a thin mattress or pad placed over a bed for additional comfort
Example
The overlet makes the bed more comfortable to sleep on.
欧弗雷特使床铺更适合睡觉。
C2 noun /ˈɒlɪv bɑːb/

Olive barb

橄榄鲃
Meaning
A small freshwater fish with olive-colored body and barbels
Example
The olive barb is commonly found in South Asian rivers.
橄榄鲃常见于南亚的河流中。
B2 adjective /əˈpəʊzd/

opposed

反对的
Meaning
being against or in disagreement with something
Example
She is strongly opposed to animal testing.
她坚决反对动物实验。
B2 noun ˈɒksɪdʒən prəˈdʌkʃən

oxygen production

氧气生产
Meaning
The process of generating oxygen through photosynthesis or other means.
Example
Plants are vital for oxygen production and the maintenance of life.
植物对于氧气生产和维持生命至关重要。
C2 noun /ˌoʊpəˈlɛsəns/

opalescence

欧泊光泽
Meaning
a milky or pearly appearance of a surface like that of an opal
Example
The pearl had a gentle opalescence under the light.
珍珠在光下有一种柔和的欧泊光泽。
A1 verb /ˈoʊpən/

open

打开
Meaning
to move something so as to allow access; to begin
Example
Please open the door for me.
请为我打开门。
C2 noun /ɔːˈreɪʃən/

oration

演讲
Meaning
A formal speech, especially one given on a ceremonial occasion
Example
The president delivered an inspiring oration.
总统发表了鼓舞人心的演讲。
C1 noun /ˈɒn.slɔːt/

onslaught

猛攻
Meaning
A fierce or destructive attack.
Example
The village faced an onslaught of enemy forces.
这个村庄面临敌军的猛烈进攻。
C2 noun /ˈoʊvərlɔːrd/

overlord

领主
Meaning
A ruler, master, or person of great power and authority over others.
Example
The peasants were forced to pay taxes to their overlord.
农民被迫向他们的领主交税。
C2 adjective /ˈoʊ.kən/

oaken

由橡木制成
Meaning
made of or resembling oak wood
Example
The villagers gathered around the oaken table in the hall.
村民们围着大厅里的橡木桌子聚集在一起。
C1 noun ˌɒb.səˈlɛs.əns

obsolescence

淘汰
Meaning
The process of becoming obsolete or outdated and no longer used.
Example
The rapid advancement of technology leads to the obsolescence of old devices.
科技的快速发展导致旧设备的淘汰。
C1 adjective /ˌɒmnɪˈprezənt/

omnipresent

无所不在
Meaning
(of God) present everywhere at the same time.
Example
Social media has become an omnipresent force in modern society.
社交媒体已成为现代社会中无所不在的力量。
A1 pronoun /ˈʌðərz/

others

其他
Meaning
people or things distinct from the ones already mentioned or known
Example
I like to spend time with others.
我喜欢和其他人一起度过时间。
C2 noun /ˌɔːrdɪˈneɪʃən/

ordination

任职
Meaning
The ceremony of conferring holy orders or official religious authority.
Example
The church held a special service for the ordination of new priests.
教堂为新神父举行了一个特别的服务，进行圣职任命。
B2 noun /ˌɒpəˈzɪʃən/

opposition

反对
Meaning
the action of opposing or resisting something
Example
The opposition to the new law was strong.
对新法律的反对很强烈。
C2 noun /ˌɒktədʒəˈnɛəriən/

octogenarian

八十岁老人
Meaning
A person who is between 80 and 89 years old.
Example
The octogenarian still jogs every morning to stay healthy.
这位八十岁老人仍然每天早上跑步以保持健康。
B2 noun /ˈɒkjʊpənt/

occupant

乘客
Meaning
A person who resides in or is present in a house, vehicle, seat, or place.
Example
The car had three occupants at the time of the accident.
事故发生时，车上有三名乘客。
C1 adjective /ˌaʊt əv ðə ˈweɪ/

out-of-the-way

偏远的或不寻常的
Meaning
remote or unusual; not in a convenient or usual location
Example
They stayed in an out-of-the-way village.
他们住在一个偏远的村庄里。
B2 adjective /aʊtˈstændɪŋ/

outstanding

杰出
Meaning
extremely good or impressive; not yet resolved or paid
Example
She received an award for her outstanding performance.
她因出色的表现获得了奖项。
B2 adjective + noun ˈɒptɪməl ˈtempərətʃər

optimal temperature

最佳温度
Meaning
The best or most favorable temperature for a particular purpose
Example
Winter provides optimal temperature for farming.
冬天提供了农业的最佳温度。
C2 noun /ˌɔːrnɪˈθɒlədʒɪst/

ornithologist

鸟类学家
Meaning
a scientist who studies birds
Example
The ornithologist spent years studying migratory birds.
这位鸟类学家花了多年时间研究迁徙鸟类。
B2 verb /ˌoʊvərˈduː/

overdo

做得过火
Meaning
to do something too much; to exaggerate or carry to excess
Example
Don't overdo the exercise on your first day at the gym.
第一天去健身房时不要运动过度。
C2 noun /ˈoʊdiəm/

odium

憎恶
Meaning
general or widespread hatred or disgust directed toward someone as a result of their actions
Example
The scandal brought public odium on the corrupt minister.
丑闻让腐败的部长蒙受了公众的憎恶。
C1 adjective /ˌɑːpərˈtuːn/

opportune

合适的时刻
Meaning
Happening at a suitable or convenient time.
Example
She arrived at an opportune moment to help.
她在合适的时刻到达，准备帮助。
B2 adverb /ˈaʊtraɪt/

Outright

直接; 完全; 毫不保留
Meaning
completely; directly; without reservation or concealment
Example
She rejected the proposal outright.
她直接拒绝了那个提案。
B2 noun oʊˈbiː.sə.t̬i

obesity

肥胖症
Meaning
The condition of being grossly fat or overweight.
Example
Obesity increases the risk of diabetes and heart disease.
肥胖症增加糖尿病和心脏病的风险。
C1 adjective /ˈɒptɪk/

optic

光学的
Meaning
Relating to the eye or vision.
Example
The optic nerve carries signals from the eye to the brain.
视神经将信号从眼睛传递到大脑。
C1 verb /ˌaʊtˈstrɪp/

outstrip

超越
Meaning
To go faster or do better than someone or something; to surpass.
Example
The company outstripped its competitors in sales last year.
公司在去年超越了它的竞争对手。
C2 verb /ˈɒsɪfaɪ/

ossify

骨化
Meaning
to turn into bone or become rigid and inflexible
Example
With age, some tissues tend to ossify.
随着年龄的增长，一些组织会变得僵硬。
C1 adjective /əbˈnɒkʃəs/

Obnoxious

令人讨厌的；惹人厌的；极其讨厌的
Meaning
extremely unpleasant; offensive; annoying
Example
His obnoxious behavior at the party annoyed everyone.
他在聚会上的令人讨厌的举止惹恼了在场的每一个人。
C1 noun /ˈɒstrəsɪzəm/

ostracism

排斥
Meaning
The act of excluding someone from a group or society.
Example
The student faced ostracism after breaking the rules.
学生在违反规则后遭受了排斥。
B2 verb /əˈfend/

offend

冒犯
Meaning
to cause displeasure or resentment; to hurt someone's feelings
Example
His rude comments offended many people at the meeting.
他的粗鲁评论冒犯了会议上的许多人。
B2 noun ˈoʊzoʊn dɪˈpliʃən

ozone depletion

臭氧消耗
Meaning
The reduction in the amount of ozone in the Earth's stratosphere, leading to increased UV radiation.
Example
Ozone depletion increases UV radiation.
臭氧消耗增加了紫外线辐射。
C2 noun /ˈɔːrdnəns/

ordnance

军火
Meaning
Military supplies including weapons, ammunition, and combat equipment.
Example
The army stored ordnance in a secure facility outside the city.
军队在城市外的一个安全设施中存储军火。
C2 adjective /ˈoʊ.pən ˈhɑrt.ɪd/

Open-hearted

开放的心; 慷慨和真诚; 热情接纳;
Meaning
Kind and generous; sincere and honest; warmly receptive;
Example
She welcomed the strangers with an open-hearted smile and invited them for dinner.
她以开放的微笑欢迎陌生人，并邀请他们共进晚餐。
C2 noun /ɑːlˈfækʃən/

olfaction

嗅觉
Meaning
The sense of smell; the process of detecting and perceiving odors.
Example
Dogs have a highly developed sense of olfaction.
狗的嗅觉非常发达。
C2 verb /ˈɑːblɪˌɡeɪt/

obligate

强迫
Meaning
to bind legally or morally; to compel someone to do something
Example
The contract obligates the company to provide timely service.
合同使公司有义务提供及时服务。
B1 noun /ˌɒpəˈreɪʃən/

operation

手术
Meaning
an act or process of functioning or operating
Example
The hospital performed a successful operation.
医院进行了成功的手术。
C1 adverb /ˈaʊtwədli/

Outwardly

表面上; 外观上;
Meaning
on the surface; externally; in appearance
Example
Outwardly, he seemed calm, but inside he was nervous.
表面上，他看起来很冷静，但内心却很紧张。
B2 noun /ˈɑp.tə.mɪst/

Optimist

乐观主义者
Meaning
a person who tends to be hopeful and confident about the future; someone who sees the good side of things
Example
As an optimist, she always believed things would improve.
作为乐观主义者，她一直相信事情会变得更好。
C2 noun /ˈoʊ.kəm/

oakum

旧绳纤维
Meaning
loose fibers obtained by untwisting old ropes, used for caulking ships
Example
The shipbuilders used oakum to seal the gaps in the wooden planks.
造船工人使用欧卡姆来密封木板之间的缝隙。
C1 adjective /ˈɔːrθədɑːks/

orthodox

Meaning
conforming to traditional beliefs or practices
Example
He comes from a very orthodox family.
C1 noun /ˌɒbstəˈtrɪʃən/

obstetrician

产科医生
Meaning
A doctor specializing in pregnancy, childbirth, and women's reproductive health.
Example
The obstetrician monitored the mother’s health throughout the pregnancy.
产科医生在整个怀孕过程中监测了母亲的健康。
B2 noun /ˈaʊt.laɪn/

Outline

大纲; 轮廓; 摘要
Meaning
a general description or plan showing the essential features of something; the main points
Example
The teacher provided an outline of the course syllabus.
老师提供了课程大纲。
C2 adjective /ˈɒsiəs/

osseous

骨质的
Meaning
consisting of or turned into bone; bony
Example
The fossil showed osseous structures of the ancient creature.
化石展示了古老生物的骨质结构。
A1 adjective /əʊˈkeɪ/

okay

没问题
Meaning
used to express agreement or acceptance
Example
It's okay to leave early today.
今天早些离开没问题。
B2 noun/verb /ˈoʊvərˌdoʊs/

overdose

过量服药
Meaning
An excessive and dangerous amount of a drug; to take too much of a substance.
Example
He was rushed to the hospital after a drug overdose.
他因毒品过量被送进了医院。
C1 adjective /ˌəʊ.vərˈɑː.tʃɪŋ/

overarching

总体, 包容, 全面
Meaning
Comprehensive or all-embracing; forming an arch over something.
Example
The overarching theme of the book is human resilience.
这本书的总体主题是人类的韧性。
C1 noun /ˈoʊvərˌtoʊn/

overtone

微妙的含义
Meaning
A subtle quality, implication, or additional meaning beyond the obvious.
Example
His speech had political overtones that were hard to ignore.
他的演讲具有政治性含义，难以忽视。
B2 noun /ˈɔɪ.stər/

Oyster

生蚝
Meaning
a type of shellfish that can be eaten and sometimes contains pearls
Example
She ordered fresh oysters at the seafood restaurant.
她在海鲜餐厅点了新鲜的生蚝。
C2 noun /ˈaʊtˌrɪɡər/

outrigger

稳定结构
Meaning
a projecting structure on a boat, used for stability, or a boat fitted with such support
Example
The fisherman paddled his outrigger canoe across the lagoon.
渔民划着带有支撑的独木舟穿过泻湖。
C2 noun /ˌɔːrnɪˈθɑːlədʒi/

ornithology

鸟类学
Meaning
the scientific study of birds
Example
She pursued ornithology to understand the migration patterns of birds.
她追求鸟类学以了解鸟类的迁徙模式。
A2 noun əˈlɪm.pɪk ɡeɪmz

Olympic Games

奥林匹克运动会
Meaning
The world's largest international sports competition held every four years, bringing together athletes from different countries to compete in various sports.
Example
The Olympic Games bring together the world's top athletes.
奥林匹克运动会汇聚了世界上最顶尖的运动员。
C2 verb /ˈɑːbdʒərˌɡeɪt/

objurgate

严厉批评
Meaning
to scold or rebuke severely
Example
The teacher objurgated the student for being dishonest.
老师因为学生不诚实而严厉批评了他。
C2 noun /ˈɒn.rʌʃ/

onrush

突如其来的冲击
Meaning
A sudden powerful forward or downward rush or flow.
Example
The onrush of water swept away the bridge.
水流的突如其来冲击冲走了桥梁。
B1 noun ˌɔː.ɡən.aɪˈzeɪ.ʃən

organization

组织
Meaning
An organized group of people with a particular purpose, such as a business or government department.
Example
The organization was officially inaugurated in 2024.
该组织于2024年正式启用。
C1 noun /ˌɑːsɪˈleɪʃən/

oscillation

摆动
Meaning
The movement back and forth at a regular speed.
Example
The oscillation of the pendulum controls the clock.
摆锤的摆动控制着时钟。
B1 noun ˈɒk.sɪ.dʒən

oxygen

氧气。无色、无味的气体，是生命必不可少的成分。
Meaning
A colorless, odorless reactive gas, the chemical element of atomic number 8 and the life-supporting component of the air.
Example
Oxygen is vital for life.
氧气对生命至关重要。
A2 adjective /əˈlɪmpɪk/

olympic

奥林匹克
Meaning
related to the Olympic Games, a major international sporting event
Example
She trained hard to compete in the Olympic Games.
她努力训练，为了参加奥林匹克运动会。
C1 verb /əbˈstrʌkt/

obstruct

阻碍
Meaning
to block or hinder progress; to prevent or impede movement
Example
The fallen tree obstructed the road for several hours.
倒下的树挡住了路几个小时。
A1 adjective /ˈɔːr.ɪndʒ/

Orange

橙色
Meaning
having a color between red and yellow like that of a ripe orange fruit
Example
The orange sunset painted the sky magnificently.
橙色的日落把天空画得非常壮丽。
A2 noun /ˈɒf.ɪs/

office

办公室
Meaning
a room or building where people work, usually at desks
Example
She left the office early to attend a family event.
她提前离开办公室去参加家庭活动。
C1 verb /aʊst/

oust

驱逐
Meaning
To remove someone from a position or place of power or authority.
Example
The rebels ousted the dictator from power.
叛乱者将独裁者赶下台。
B1 adjective /ˌoʊvərˈweɪt/

overweight

超重
Meaning
heavier than is considered healthy or normal
Example
The doctor advised him to lose weight as he was overweight.
医生建议他减肥，因为他超重。
C1 noun /ˈɒktɪv/

octave

Meaning
A series of eight musical notes, or the interval between one musical pitch and another with double its frequency.
Example
The singer's voice could easily reach the higher octave.
B2 adverb /ˌoʊvərˈnaɪt/

Overnight

一夜之间; 突然; 非常快速
Meaning
during the night; suddenly; very quickly
Example
The city was transformed overnight.
这座城市一夜之间发生了变化。
C2 adjective /əbˈstrɛpərəs/

obstreperous

喧闹且难以控制
Meaning
Noisy and difficult to control.
Example
The obstreperous students disrupted the class.
那些喧闹的学生打乱了课堂。
C2 noun /oʊliˈændər/

Oleander

夹竹桃
Meaning
a poisonous evergreen shrub with clusters of white, pink, or red flowers
Example
The beautiful oleander flowers bloomed in the garden despite their toxic nature.
美丽的夹竹桃花在花园里盛开，尽管它们有毒。
C1 adjective /əbˈsɛsɪv/

obsessive

强迫症的
Meaning
Relating to or characterized by an obsession; thinking about something too much.
Example
He has an obsessive interest in cleanliness.
他对清洁有强迫症的兴趣。
A2 adjective /ɒd/

Odd

奇怪的; 不寻常的; 不同于正常或预期的
Meaning
strange; unusual; different from what is normal or expected
Example
That's an odd way to solve the problem.
那是解决问题的一种奇怪方式。
C1 noun /ˈɒfʃuːt/

offshoot

分支
Meaning
A branch or result that develops from something larger or more important.
Example
The startup was an offshoot of a major tech company.
这家初创公司是一个大型科技公司分支。
C2 noun /əˈblɪkwɪti/

obliquity

歪曲
Meaning
Deviation from moral or usual conduct; indirectness or lack of straightforwardness.
Example
The politician was criticized for the obliquity of his answers.
那位政治家因其回答的歪曲性而受到批评。
C2 noun /əbˈstrʌkʃənɪst/

obstructionist

Meaning
a person who deliberately delays or prevents progress by being uncooperative or oppositional
Example
The obstructionist in the committee kept delaying the decision-making process.
C1 adjective /ˈɒm.ɪ.nəs/

Ominous

不祥的; 威胁的
Meaning
giving the impression that something bad will happen; threatening; foreboding
Example
The dark clouds looked ominous before the storm.
暴风雨前，黑云看起来预示着灾难。
B2 verb /ˌoʊvərˈloʊd/

overload

过载
Meaning
to load with too much weight or cargo; to give too much work or information
Example
Don't overload the washing machine or it might break down.
不要过载洗衣机，否则它可能会坏掉。
C2 adjective /ˌoʊpəˈlɛsənt/

opalescent

欧泊色的
Meaning
showing or reflecting a milky, iridescent light like an opal
Example
The opalescent sky glowed with shades of pink and blue.
欧泊色的天空闪烁着粉色和蓝色的色调。
C1 verb /ˌoʊvərˈpaʊər/

overpower

征服
Meaning
To defeat or gain control over someone or something by using greater strength or force.
Example
The soldiers managed to overpower the enemy forces.
士兵们成功压倒了敌军。
B1 adjective /əˈkeɪ.ʒən.əl/

Occasional

偶然的
Meaning
occurring infrequently or irregularly; happening from time to time
Example
She enjoys occasional walks in the park.
她喜欢在公园里偶尔散步。
C1 noun /ˈɑd.ɪ.ti/

Oddity

奇异现象
Meaning
something that is strange or unusual; a peculiar trait
Example
His habit of sleeping standing up was considered an oddity.
他站着睡觉的习惯被视为一种奇异现象。
C1 noun /ˌɑːk.sɪˈmɔːr.ɒn/

oxymoron

矛盾修饰法
Meaning
a figure of speech where two contradictory terms are combined
Example
The phrase 'deafening silence' is a classic oxymoron.
短语 '震耳欲聋的寂静' 是一个经典的矛盾修饰法。
B2 noun ˈəʊnəʃɪp

ownership

所有权
Meaning
The act, state, or right of possessing something; legal title to something.
Example
Ownership of resources was crucial.
资源的所有权至关重要。
C2 noun /ˈɔːfəl/

offal

内脏
Meaning
the internal organs and entrails of an animal used as food; waste parts
Example
The butcher prepared sausages using pork offal.
屠夫使用猪的内脏做香肠。
A2 noun /ˈoʊ.ʃən/

ocean

海洋
Meaning
A very large expanse of sea, especially the main areas of sea between continents.
Example
The ocean covers more than 70% of the Earth's surface.
海洋覆盖了地球表面超过70%。
C1 adverb /ˈɒp.tɪ.məl.i/

optimally

最优地
Meaning
In the most effective or efficient way possible.
Example
Tasks should be allocated optimally for maximum output.
任务应当最优地分配，以实现最大产出。
C2 noun /ˈɒfərtɔːri/

offertory

奉献
Meaning
The part of a religious service when offerings are collected; the offering itself.
Example
The offertory was taken during the Sunday service.
奉献在星期日的礼拜期间收集。
C1 adjective /əˈprɛs.ɪv/

Oppressive

压迫的
Meaning
Harsh and authoritarian; overwhelming; causing distress; tyrannical;
Example
The oppressive heat made it difficult to work outside during the summer.
压迫性的热浪使得夏天在外工作变得很困难。
C1 noun /əbˈzɜːrvətɔːri/

observatory

天文台
Meaning
A building equipped for observing astronomical or meteorological events.
Example
The observatory is open to the public on weekends.
天文台在周末对公众开放。
B1 verb /ˈɒpəreɪtɪŋ/

operating

操作
Meaning
to control or manage the functioning of something
Example
The company has been operating in this market for five years.
公司已经在这个市场运营了五年。
B2 adjective /ˈɔɪl.i/

Oily

油腻的; 油覆盖的; 油滑的
Meaning
covered with oil; containing oil; greasy
Example
Her oily skin needs special care.
她的油腻皮肤需要特别护理。