Omen
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C1 noun /ˈoʊ.mən/

Omen

未来好运或厄运的征兆
Meaning
an event regarded as a sign of future good or bad luck
Example
Many people consider a black cat crossing your path a bad omen.
许多人认为一只黑猫横穿你的路是一个坏预兆。
A1 pronoun /aʊər/

our

我们的
Meaning
belonging to or associated with the speaker and one or more other people
Example
This is our house.
这是我们的房子。
C1 adjective /əbˈzɜːrvənt/

Observant

观察力强的
Meaning
quick to notice things; watchful; attentive
Example
The observant detective noticed every small detail at the crime scene.
观察力强的侦探注意到了犯罪现场的每个细节。
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。
B2 noun /ˌɒb.zəˈveɪ.ʃənz/

observations

观察
Meaning
The action or process of observing something carefully.
Example
Observations of distant galaxies provide new insights.
对遥远星系的观察提供了新的见解。
C2 noun /ˈɒbsɪkwi/

obsequy

葬礼仪式
Meaning
A funeral rite, usually used in plural form obsequies.
Example
The village gathered for the obsequy of their beloved teacher.
村庄聚集在一起，参加他们心爱的老师的葬礼。
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 /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。
C1 adjective /ˌoʊvərˈbloʊn/

overblown

夸张
Meaning
excessively exaggerated or inflated
Example
The controversy was overblown by the media.
媒体过度夸大了争议。
C2 verb /ˈɑːskjʊleɪt/

osculate

亲吻
Meaning
To kiss.
Example
They osculated under the mistletoe during the party.
他们在派对上在槲寄生下接吻。
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。
C2 noun /oʊˈbeɪsəns/

obeisance

敬礼
Meaning
A gesture of respect such as a bow or curtsy.
Example
They bowed in obeisance to the king.
他们向国王行了敬礼。
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。
B2 noun/verb /ˌoʊvərˈlæp/

overlap

Meaning
To extend over and cover partly; an area where things coincide.
Example
The two meetings overlap by an hour.
B2 noun /ˈaʊtskɜːrts/

outskirts

城市边缘
Meaning
The outer parts of a town or city, away from the center.
Example
They moved to the outskirts of the city for a quieter life.
他们为了更安静的生活搬到了城市的边缘。
A1 pronoun, noun, adjective /wʌn/

one

一
Meaning
the number equivalent to the sum of zero and one; a single person or thing
Example
Only one student answered the question.
只有一个学生回答了问题。
C1 noun /ˈɔːrθədɑːksi/

orthodoxy

正统
Meaning
traditional or generally accepted beliefs and practices
Example
The religious leader defended the orthodoxy of the faith.
宗教领袖捍卫了信仰的正统性。
C2 adjective /əbˈtruːsɪv/

obtrusive

干扰的
Meaning
noticeable in an unpleasant or unwelcome way; intrusive
Example
The advertisement was so obtrusive that it ruined the user’s experience.
广告如此显眼，以至于破坏了用户体验。
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。
B2 noun /ˌɑb.lɪˈɡeɪ.ʃən/

Obligation

义务
Meaning
a duty or commitment; something that must be done legally or morally
Example
Parents have an obligation to care for their children.
父母有责任照顾他们的孩子。
B2 noun /ˈɔːrɡənaɪzər/

organizer

组织者
Meaning
a person who arranges or coordinates activities, events, or groups; a tool or item used to keep things in order
Example
She worked as the main organizer of the international conference.
她是这次国际会议的主要组织者。
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。
A1 interjection /oʊ/

oh

哦
Meaning
used to express surprise, realization, or understanding
Example
Oh, I didn't know you were here!
哦，我不知道你在这里！
C1 adjective /ˌɒbsəˈliːt/

obsolete

过时的
Meaning
No longer in use or out of date.
Example
Floppy disks are now completely obsolete.
软盘现在完全过时了。
C2 noun /ˈɒkjʊlɪst/

oculist

眼科医生
Meaning
An old-fashioned term for an eye doctor or ophthalmologist.
Example
The village oculist was known for treating various eye diseases.
村里的眼科医生以治疗各种眼病而闻名。
B2 noun /ˈaʊtˌbreɪk/

outbreak

爆发
Meaning
a sudden start or occurrence of something unpleasant, like disease or violence
Example
There was an outbreak of flu in the city.
城市中爆发了流感。
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。
A1 noun/adjective/adverb /ˌaʊtˈsaɪd/

outside

外面
Meaning
the external part or surface of something; beyond the boundary
Example
Children were playing outside in the yard.
孩子们在院子外面玩。
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 /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 /ˌoʊvərˈiːt/

overeat

幸福
Meaning
To eat more food than the body needs.
Example
She tends to overeat when she is stressed.
她在收到奖项时无法掩饰自己的幸福。
A2 verb /ˈɔːfər/

offer

提供
Meaning
to present something for acceptance or rejection; to propose
Example
She offered to help with the project.
她提出帮助这个项目。
B2 noun /ɔːˈræŋ.ʊˌtæŋ/

Orang-Outang

猩猩
Meaning
a large arboreal ape with long reddish hair, long arms, and hooked hands and feet, native to Borneo and Sumatra
Example
The orangutan swings gracefully through the forest canopy.
猩猩优雅地穿越森林的树冠。
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 /ˈɒp.tɪ.maɪz/

optimize

优化
Meaning
To make the best or most effective use of a situation, opportunity, or resource.
Example
The company is working to optimize its supply chain.
公司正在努力优化其供应链。
C2 adjective /ˌoʊdəˈrɪfərəs/

odoriferous

芬芳的
Meaning
having or giving off a smell, especially a strong or pleasant one
Example
The garden was filled with odoriferous flowers.
花园里充满了芬芳的花朵。
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。
C1 verb /ɔːrˈdeɪn/

ordain

Meaning
To officially make someone a priest or minister; to decree or order something officially.
Example
The bishop will ordain three new priests this Sunday.
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。
B1 adjective /ˈaʊtər/

outer

外部
Meaning
situated on or toward the outside; external
Example
The outer layer of the jacket is waterproof.
夹克的外层是防水的。
B2 adjective /ˈɔː.də.li/

Orderly

有序的; 系统的; 平静的
Meaning
well-organized; systematic; peaceful
Example
Please keep your desk orderly and clean.
请保持您的桌面整齐和干净。
C1 verb /ˈoʊvərˌhɔːl/

overhaul

全面改革
Meaning
to examine thoroughly and repair or improve something that is worn or ineffective
Example
The company decided to overhaul its outdated computer system.
公司决定彻底改革其过时的计算机系统。
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。
C2 noun /ˈoʊɡər/

ogre

Meaning
A mythical monster, often depicted as large, hideous, and cruel; metaphorically, a cruel or terrifying person.
Example
The villagers feared the ogre who lived in the dark forest.
A2 noun /ˈoʊ.nər/

Owner

所有者
Meaning
a person who owns something; someone who has legal possession of property
Example
The owner of the restaurant greeted us warmly.
餐厅的所有者热情地迎接了我们。
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。
C1 noun ˈaʊt.sɔːr.sɪŋ

outsourcing

外包
Meaning
The practice of having certain job functions done outside a company instead of having an in-house department or employee handle them.
Example
Many companies use outsourcing to reduce labor costs.
许多公司使用外包来降低劳动力成本。
B2 noun /ˈɒfərɪŋ/

offering

提供
Meaning
something that is given, especially as a gift or contribution
Example
The company’s latest offering is an eco-friendly car.
公司的最新产品是一款环保汽车。
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 /ˈɒktəɡən/

octagon

八边形
Meaning
A polygon with eight sides and eight angles.
Example
The stop sign is shaped like an octagon.
停车标志呈八边形。
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。
A1 pronoun /aʊərz/

ours

我们的
Meaning
belonging to or associated with us
Example
This victory is ours.
这个胜利是我们的。
C1 noun /ˈɔːr.ə.tɔːr.i/

oratory

演讲艺术
Meaning
The art of public speaking; skilled and confident delivery of speeches to an audience.
Example
His exceptional oratory skills won him the debate competition.
他出色的演讲技巧使他赢得了辩论比赛。
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。
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。
C2 verb /əbˈtruːd/

obtrude

强行介入
Meaning
to force oneself or one's ideas into a situation uninvited or inappropriately
Example
He didn’t want to obtrude into their private conversation.
他不想打扰他们的私人对话。
C2 adjective /ɔːrˈθɑːɡənl/

orthogonal

正交
Meaning
at right angles; independent or unrelated
Example
In mathematics, two vectors are orthogonal if their dot product is zero.
在数学中，如果两个向量的点积为零，它们就是正交的。
C2 adjective /ˈəʊ.dər.əs/

Odorous

芬芳的; 香气的
Meaning
having a strong smell; fragrant; aromatic
Example
The garden was filled with odorous flowers.
花园里充满了芬芳的花朵。
C1 adjective /ˌɔːrθəˈpiːdɪk/

orthopedic

与骨骼或肌肉畸形的矫正有关
Meaning
Relating to the correction of deformities of bones or muscles.
Example
She visited an orthopedic surgeon for her back pain.
她因为背痛去看了骨科医生。
C1 noun /ˈaʊtˌɡroʊθ/

outgrowth

衍生物
Meaning
something that grows out of something else; a natural development or result
Example
The new policy was an outgrowth of years of debate.
新政策是多年辩论的衍生物。
C1 verb /ˈɒs.ɪ.leɪt/

oscillate

在两个点或状态之间来回摆动或移动
Meaning
To swing or move back and forth between two points or states
Example
The stock market tends to oscillate during uncertain times.
股市在不确定的时期往往会波动。
B2 adjective ˌɒp.ərˈeɪ.ʃən.əl

operational

操作的
Meaning
In working order; ready for use.
Example
The space project will be operational by 2025.
太空项目将在2025年投入使用。
B1 adjective /əˈbiː.di.ənt/

Obedient

顺从的
Meaning
willing to comply with orders or instructions; submissive
Example
The obedient student always follows the teacher's instructions.
听话的学生总是遵循老师的指示。
B2 verb /əˈpoʊz/

oppose

反对
Meaning
to disagree with or resist; to act against
Example
Many citizens oppose the new tax policy.
许多公民反对新的税收政策。
C1 adjective /ɔːˈneɪt/

ornate

华丽的
Meaning
elaborately or highly decorated
Example
The palace hall was filled with ornate furniture and paintings.
宫殿的大厅里充满了华丽的家具和画作。
C1 noun /oʊˈeɪ.sɪs/

Oasis

绿洲
Meaning
a fertile spot in a desert where water is found; a pleasant refuge
Example
The travelers found an oasis after days in the desert.
旅行者在沙漠中几天后找到了一个绿洲。
A2 adjective /ˈɒb.vi.əs/

Obvious

显而易见的; 容易理解的
Meaning
easily perceived or understood; clear and apparent to the mind
Example
It was obvious that she was upset about something.
很明显，她因某事而不高兴。
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。
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。
B1 adjective /ˈɔːɡənaɪzd/

organized

有条理的
Meaning
Arranged in a systematic way, especially on a large scale.
Example
An organized approach to work increases productivity and reduces stress.
有条理的工作方法可以提高生产力并减少压力。
C2 noun /ˌɑːpərˈtuːnɪzəm/

opportunism

机会主义
Meaning
The practice of taking advantage of opportunities regardless of principles or ethics.
Example
His decision was driven by opportunism, not values.
他的决定是由机会主义驱动的，而不是由价值观驱动的。
B1 noun /ˈɔr.ə.ʒɪn/

Origin

起源
Meaning
the point or place where something begins, arises, or is derived; the source
Example
Scientists are studying the origin of the universe.
科学家正在研究宇宙的起源。
C1 noun /ˌoʊvərprəˈdʌkʃən/

overproduction

过度生产
Meaning
The act of producing more of something than is needed or can be consumed.
Example
The economic crisis was caused by the overproduction of goods.
经济危机是由商品的过度生产引起的。
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 adjective /ˈaʊtˌɡoʊɪŋ/

outgoing

外向
Meaning
Friendly and sociable; inclined to mix with others.
Example
He is an outgoing person who loves meeting new people.
他是一个外向的人，喜欢结识新朋友。
B1 verb /əbˈzɜːrv/

observe

观察
Meaning
to watch carefully; to notice or perceive something
Example
Scientists observe the behavior of animals in the wild.
科学家观察野生动物的行为。
C1 noun /ˌɑːpərˈtuːnɪst/

opportunist

机会主义者
Meaning
A person who takes advantage of situations for personal gain, often disregarding principles.
Example
He is seen as an opportunist who always puts his interests first.
他被看作是一个机会主义者，总是把自己的利益放在第一位。
A2 adjective /ˈaʊtdɔːr/

outdoor

户外
Meaning
situated, existing, or done outside a building
Example
We planned an outdoor picnic for the weekend.
我们计划了一个户外野餐，周末进行。
C2 noun ˈɒpjʊləns

opulence

奢华
Meaning
Great wealth or luxuriousness.
Example
The opulence of the mansion was evident in its ornate furnishings.
大厦的奢华体现在其华丽的家具中。
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。
C2 verb /ˌoʊvərˈliːp/

overleap

跳过
Meaning
To jump over something; to omit or disregard something.
Example
He managed to overleap the fence easily.
他轻松地越过了栅栏。
B1 noun /əˈpɪn.jən/

Opinion

意见
Meaning
a view or judgment formed about something; a belief or assessment based on grounds short of proof
Example
In my opinion, this is the best solution.
在我看来，这是最好的解决方案。
B2 noun /ɒpˈtɪʃən/

optician

眼镜师
Meaning
A person who makes or sells glasses and contact lenses.
Example
The optician adjusted my new glasses to fit better.
眼镜师调整了我的新眼镜，以便更好地适应。
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。
C1 noun /əˈpreʃ.ən/

Oppression

压迫; 虐待; 暴政;
Meaning
cruel or unjust treatment or exercise of authority; the state of being subject to harsh treatment
Example
The people fought against political oppression.
人民反对政治压迫而斗争。
C2 noun /ˈɔː.rɪ.fɪs/

orifice

孔
Meaning
an opening or hole, especially in the body or a device
Example
The medicine was applied through a small orifice in the device.
药物通过设备上的一个小孔应用。
B2 verb /ɒpt/

opt

选择
Meaning
to choose or decide to do something instead of something else
Example
Many students opt to study abroad for better opportunities.
许多学生选择出国留学以获得更好的机会。
A2 noun /ˈɒpərə/

opera

歌剧
Meaning
a dramatic performance in which the actors sing most of their lines
Example
We watched a beautiful opera at the theater last night.
我们昨晚在剧院观看了一场美丽的歌剧。
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。
B2 verb /ˌoʊvərˈteɪk/

overtake

超过
Meaning
to catch up with and pass someone or something; to surpass
Example
The runner managed to overtake his competitor in the final lap.
跑步者在最后一圈超过了他的竞争对手。
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。
B2 verb /oʊˈmɪt/

omit

遗漏
Meaning
to leave out or exclude; to fail to include something
Example
Please don't omit any important details from your report.
请不要遗漏报告中的重要细节。
B1 adjective /ˌoʊld ˈfæʃənd/

old-fashioned

过时的
Meaning
not modern; belonging to an earlier time
Example
He still wears an old-fashioned hat.
他仍然戴着一顶过时的帽子。
C2 verb /əbˈvɜːrt/

obvert

反转
Meaning
To turn something so as to face in a different direction; in logic, to convert a proposition by negating both subject and predicate.
Example
The teacher asked the students to obvert the statement for practice.
老师要求学生练习将声明进行奥贝特。
C1 adjective /ˌaʊt ən ˈaʊt/

out-and-out

完全
Meaning
complete; absolute; used to emphasize something extreme
Example
The speech was an out-and-out lie.
这个演讲是一个完全的谎言。
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。
C1 adjective/adverb /ˌɒfˈhænd/

offhand

草率
Meaning
Without previous thought or preparation; casual and sometimes dismissive.
Example
She gave an offhand reply to his serious question.
她对他严肃的问题做出了一个草率的回答。
B2 noun /ˈaʊtlet/

outlet

出口
Meaning
a means by which something is released, expressed, or distributed
Example
Art is a great outlet for emotions.
艺术是情感的一个极好的出口。
B2 verb /əˈrɪdʒɪneɪt/

originate

起源
Meaning
to come into existence; to begin; to create or produce
Example
The tradition originated in ancient times.
这个传统起源于古代。
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 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。
B1 adverb /əˈkeɪʒənəli/

Occasionally

偶尔; 有时;
Meaning
sometimes; from time to time; not regularly
Example
I occasionally visit my grandmother on weekends.
我偶尔在周末去看望我的祖母。
B1 noun /ˈɑp.ʃən/

Option

选项
Meaning
a thing that is or may be chosen; an alternative course of action
Example
You have the option to work from home or office.
你可以选择在家工作或在办公室工作。
C1 noun /əbˈzɜːvəns/

observance

遵守
Meaning
The practice of following a custom, rule, or religious law.
Example
The festival is held in observance of a centuries-old tradition.
该节庆是为了遵守一项百年传统而举行的。
C1 noun /ˈəʊ.nəs/

onus

责任
Meaning
A duty or responsibility, especially a heavy one.
Example
The onus is on the government to provide relief to the victims.
政府有责任向受害者提供援助。
C1 adjective /oʊˈvɜːrt/

overt

公开的
Meaning
Done or shown openly; not hidden or secret.
Example
There was an overt display of hostility between the rivals.
在对手之间有一种公开的敌意表现。
B2 noun /oʊˈbiː.di.əns/

Obedience

服从
Meaning
compliance with an order, request, or law; submission to authority
Example
Children should show obedience to their parents.
孩子们应该对父母表现出服从。
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。
B2 adjective /ˈɒp.tɪ.məl/

optimal

最优，最适合的
Meaning
Best or most favorable; the most effective under particular conditions.
Example
The optimal temperature for plant growth is around 25°C.
植物生长的最优温度大约是25°C。
C2 adjective /ˈɑːsɪˌfaɪd/

ossified

变成骨头，僵硬
Meaning
Turned into bone or become rigid; unwilling to change.
Example
The company had an ossified management structure that resisted innovation.
该公司有一个僵化的管理结构，抵制创新。
B1 noun /ˌɒp.əˈtjuː.nə.ti/

opportunity

机会
Meaning
A favorable chance or set of circumstances that makes it possible to do something.
Example
She seized the opportunity to study abroad.
她抓住了去国外学习的机会。
B1 adjective /əˈrɪdʒ.ɪ.nəl/

Original

原始的; 主要的; 真实的
Meaning
first; fundamental; primary; authentic
Example
This is the original document, not a copy.
这是原始文件，不是副本。
B2 noun /ˈɔr.fən.ɪʒ/

Orphanage

孤儿院
Meaning
an institution for the care and education of children who have lost their parents
Example
The charity built a new orphanage for homeless children.
慈善机构为无家可归的孩子建了一个新孤儿院。
C2 verb ˈɑːb.fə.skeɪt

obfuscate

使模糊，掩盖，混淆
Meaning
Render obscure, unclear, or unintelligible.
Example
Politicians often obfuscate facts to mislead people.
政客们经常使事实变得模糊，以误导人民。
C1 adjective əʊˈpeɪk

opaque

不透明, 难以理解
Meaning
Not able to be seen through; not transparent; difficult to understand.
Example
The glass was too opaque to see through.
玻璃太不透明，无法看透。
C1 noun /ɔːr/

Oar

桨
Meaning
a long pole with a flat blade used to row a boat
Example
He dipped the oar into the water and pulled the boat forward.
他将桨浸入水中并拉动船向前。
C2 noun /ˌɔːrəˈtɔːri.oʊ/

oratorio

宗教音乐作品
Meaning
A large-scale musical composition for orchestra, choir, and soloists, usually on a sacred theme, performed without costumes or scenery.
Example
Handel's 'Messiah' is one of the most famous oratorios ever written.
亨德尔的《弥赛亚》是最著名的宗教音乐作品之一。
B1 verb অকার্স

occurs

发生
Meaning
Happens or takes place, especially as a result of something.
Example
Snowfall occurs in regions with freezing temperatures.
在气温低于零度的地区会发生降雪。
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。
C2 noun /ˈɒbsɪkwiːz/

obsequies

葬礼仪式
Meaning
Funeral rites or ceremonies.
Example
The obsequies for the late leader drew thousands of mourners.
已故领导人的葬礼吸引了成千上万的哀悼者。
C1 verb /ˌoʊvərˈθroʊ/

overthrow

幸福
Meaning
To remove a leader or government from power, often by force.
Example
The rebels planned to overthrow the corrupt regime.
她在收到奖项时无法掩饰她的幸福感。