overwhelm
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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.
C2 noun /ˈɑːbəlɪsk/

obelisk

方尖碑
Meaning
A tall, four-sided, narrow tapering monument with a pyramid-shaped top.
Example
The ancient Egyptians built obelisks to honor their gods.
古埃及人建造了方尖碑来纪念他们的神。
C1 adjective /ˈɒptɪkəl/

optical

光学的
Meaning
related to or used in seeing or sight
Example
The optical illusion fooled everyone at the exhibition.
光学幻觉在展览会上迷惑了所有人。
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。
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。
A2 noun /ˈɔr.dər/

Order

命令; 顺序
Meaning
a command or instruction; the arrangement of things following a particular sequence
Example
The teacher gave an order to sit down quietly.
老师下达了安静坐下的命令。
C2 noun /ɒkˈteɪvoʊ/

octavo

八开 (通过将纸张折叠成八个部分而产生的书籍大小)
Meaning
A size of book page resulting from folding a sheet of paper into eight leaves (sixteen pages).
Example
The old library contained rare octavo editions of Shakespeare.
这座古老的图书馆里有莎士比亚的稀有八开版书籍。
B2 adverb /ˈəʊvəli/

overly

过度
Meaning
to an excessive degree or extent
Example
She was overly concerned about the results.
她对结果过于担忧。
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。
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。
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。
C1 noun /ˈɒptɪks/

optics

光学
Meaning
The branch of physics dealing with light and vision.
Example
She studied optics to understand how lenses work.
她学习了光学，以了解镜头是如何工作的。
C1 verb /uːz/

ooze

渗透
Meaning
to slowly flow or leak out through small openings or pores
Example
Blood began to ooze from the small cut.
血液开始从小伤口渗透出来。
A1 verb, adjective /oʊn/

own

拥有
Meaning
to possess something; belonging to oneself
Example
She owns a beautiful house in the city.
她拥有一座漂亮的房子。
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。
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。
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。
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。
C1 adjective /əbˈstrʌk.tɪv/

Obstructive

阻碍性的
Meaning
deliberately creating difficulties or preventing progress; hindering or blocking something
Example
The obstructive policies hindered economic growth.
这些阻碍性的政策阻碍了经济增长。
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 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。
C2 noun /ˈɔɪl.mən/

Oilman

石油商
Meaning
a person who works in the oil industry; someone who sells oil or petroleum products
Example
The oilman discovered a new oil field in the desert.
石油商在沙漠中发现了一个新的油田。
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。
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。
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。
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。
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 adjective /ˌɒstɛnˈteɪʃəs/

ostentatious

炫耀的
Meaning
Characterized by a showy or pretentious display intended to impress others.
Example
He wore an ostentatious gold chain to the party.
他在派对上戴着一条炫耀的金链子。
A2 adjective /ˈɑp.ə.zɪt/

Opposite

相反的; 完全不同的; 面对面; 反向的;
Meaning
Contrary; completely different; facing each other; reverse;
Example
They have opposite views on politics but remain good friends.
他们在政治上的观点相反，但仍然是好朋友。
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 /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。
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 /ˈəʊnərəs/

onerous

繁重
Meaning
involving a great deal of effort, difficulty, or burden
Example
Fulfilling the contract proved to be an onerous task for the company.
履行合同对公司来说是一项繁重的任务。
C1 adjective /ˌaʊtˈlændɪʃ/

outlandish

奇异
Meaning
Looking or sounding bizarre or unfamiliar; strange.
Example
He wore an outlandish costume to the festival.
他穿着一件奇异的服装参加了节日。
C1 adjective /oʊˈbiːs/

obese

肥胖
Meaning
Extremely overweight; having an excessive amount of body fat.
Example
The doctor advised the obese patient to adopt a healthier lifestyle.
医生建议肥胖的病人采取更健康的生活方式。
C1 verb /ˌoʊvərˈriːtʃ/

overreach

过度伸展
Meaning
to go beyond what is proper, acceptable, or achievable; to overextend
Example
The politician overreached by making promises he couldn't keep.
那位政治家在做出无法兑现的承诺时，过度伸展了自己。
B2 noun /ˈoʊvərpæs/

overpass

立交桥
Meaning
A bridge that carries one road or railway over another.
Example
The new overpass reduced traffic congestion in the city.
新的立交桥减少了城市的交通拥堵。
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。
A2 preposition /ˈɒntu/

onto

在…上
Meaning
moving to a position on the surface of something
Example
She jumped onto the table to get the book.
她跳到桌子上去拿书。
B2 noun /ɔːrˈɡæn.ɪk ˈfɑːr.mɪŋ/

organic farming

有机农业
Meaning
Farming method that avoids synthetic chemicals and fertilizers, using natural methods instead.
Example
Organic farming improves soil health and reduces pollution.
有机农业改善了土壤健康并减少了污染。
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。
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。
B1 noun /ˈɒbstəkəlz/

obstacles

障碍
Meaning
Things that block one's way or prevent or hinder progress.
Example
Obstacles in life can often lead to valuable lessons.
生活中的障碍常常导致宝贵的教训。
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。
B2 noun /ˌɑb.zɚˈveɪ.ʃən/

Observation

观察
Meaning
the action of watching something carefully; a comment or remark
Example
The scientist made careful observations of the experiment.
科学家仔细观察了实验。
C2 noun /ˌɒpəˈrɛtə/

operetta

轻歌剧
Meaning
a short opera with light and humorous themes
Example
The theater staged a famous operetta by Gilbert and Sullivan.
剧院上演了吉尔伯特与沙利文的著名轻歌剧。
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。
B1 noun /ˌɑk.jəˈpeɪ.ʃən/

Occupation

职业; 工作; 占领
Meaning
a job or profession; the action of taking control of a place
Example
Teaching is her chosen occupation.
教学是她选择的职业。
C1 noun /ˈɑːdəsi/

odyssey

漫长的旅行
Meaning
a long, adventurous journey; a series of experiences
Example
Her career has been an odyssey of challenges and achievements.
她的职业生涯是一场挑战和成就的漫长旅行。
C1 adjective /aʊtˈmoʊdɪd/

outmoded

过时的
Meaning
No longer in fashion or useful; outdated.
Example
That old computer is completely outmoded.
那台旧电脑完全过时了。
B2 noun /ˈoʊtˌmiːl/

oatmeal

燕麦粥
Meaning
A type of porridge made from ground oats, often eaten for breakfast.
Example
She eats a bowl of oatmeal every morning for breakfast.
她每天早晨吃一碗燕麦粥当早餐。
C1 noun ˌɒp.tɪ.maɪˈzeɪ.ʃən

optimization

优化
Meaning
Improving processes to increase performance and efficiency.
Example
SEO optimization helps websites rank higher on search engines.
SEO优化帮助网站在搜索引擎中排名更高。
B2 verb /əbˈteɪn/

obtain

获得
Meaning
to get or acquire something
Example
You need to obtain a visa before traveling abroad.
你需要在出国前获得签证。
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。
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。
C2 noun /əbˈsɪdiən/

obsidian

黑曜石 (黑色的玻璃状火山岩)
Meaning
A hard, dark, glasslike volcanic rock formed by rapid solidification of lava.
Example
The knife was made from sharp obsidian.
刀是由锋利的黑曜石制成的。
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 /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 /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。
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。
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。
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。
C1 adjective /ˈɑp.ər.ə.tɪv/

Operative

有效的; 运行中的; 工作中的; 操作性的;
Meaning
Functioning; in effect; working; active;
Example
The new safety protocols became operative immediately after the accident.
新的安全协议在事故发生后立即生效。
C1 verb /ˌaʊtˈweɪ/

outweigh

比...更重要
Meaning
To be more important, valuable, or significant than something else.
Example
The benefits of the new policy outweigh the risks.
新政策的好处超过了风险。
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 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。
C1 noun əˈblɪv.i.ən

oblivion

遗忘, 灭绝, 消失
Meaning
The state of being unaware or unconscious of what is happening; complete forgetfulness.
Example
His name faded into oblivion over time.
随着时间的推移，他的名字渐渐消失在遗忘中。
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 adjective /ˌoʊvərˈbɛrɪŋ/

overbearing

专横
Meaning
unpleasantly or arrogantly domineering
Example
His overbearing attitude made everyone uncomfortable.
他的专横态度让所有人都感到不舒服。
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。
B1 adjective /ˌoʊvərˈsiːz/

overseas

海外
Meaning
in or to a foreign country across the sea
Example
He went overseas for higher education.
他去海外深造。
A1 adverb /aʊt/

out

外面
Meaning
moving or appearing away from the inside or center; not at home or present
Example
He stepped out of the room quietly.
他悄悄地走出房间。
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 /ˌoʊvərˈwɛlmɪŋ/

overwhelming

压倒性的
Meaning
Very intense; overpowering.
Example
Large tasks can feel overwhelming.
大型任务可能会让人感到压倒。
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。
C1 verb /əˈfɪʃieɪt/

officiate

主持
Meaning
To perform official duties, especially in a ceremony or as a referee.
Example
The priest will officiate the wedding ceremony.
牧师将主持婚礼仪式。
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。
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。
B2 adjective /ˌfæʃ.ənd/

Outdated

过时
Meaning
obsolete; no longer current
Example
This computer software is completely outdated.
这个软件完全过时了。
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 noun ˌɒbfəsˈkeɪʃən

obfuscation

混淆, 迷惑
Meaning
The action of making something obscure, unclear, or unintelligible.
Example
The obfuscation of the data made it difficult to interpret.
数据的混淆使得它们难以解释。
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。
B2 noun /ˌaʊtˈsaɪdə(r)/

outsider

局外人
Meaning
a person who is not accepted as a member of a particular group or community
Example
As a new student, she often felt like an outsider at school.
作为新生，她常常觉得自己在学校是个局外人。
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。
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 /ˌɑːbdʒərˈɡeɪʃən/

objurgation

严厉的斥责
Meaning
a harsh scolding or strong rebuke
Example
His misconduct earned him a severe objurgation from the manager.
他的不当行为让他受到了经理的严厉斥责。
B1 noun əbˈdʒek.tɪv

objective

目标
Meaning
A thing aimed at or sought; a goal.
Example
The main objective is to test sustainability.
主要目标是测试可持续性。
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。
B2 noun /ɒdz/

odds

可能性
Meaning
the likelihood or probability of something happening; chances for or against something
Example
The odds of winning the lottery are very low.
中彩票的机会非常小。
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。
A2 adjective /ˈɔː.dɪ.nər.i/

Ordinary

普通的; 常见的; 不特别的
Meaning
normal; usual; not special
Example
It was just an ordinary day at the office.
那只不过是办公室里的普通一天。
B2 adverb /əˈfɪʃəli/

officially

正式地
Meaning
in a formal or authorized way
Example
The building was officially opened by the mayor.
这座建筑由市长正式开幕。
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。
C1 adjective əˈblɪv.i.əs

oblivious

无意识的
Meaning
Being completely unaware of surrounding events.
Example
He was oblivious to the noise around him while reading.
他在阅读时完全没有意识到周围的噪音。
B2 verb əbˈzɜːrvd

observed

庆祝
Meaning
To celebrate or keep a religious or other festival.
Example
The day is observed annually to raise awareness.
这一天每年庆祝，以提高意识。
C1 adjective /əˈblaɪdʒɪŋ/

obliging

乐于助人
Meaning
Willing to help or do favors; accommodating.
Example
The staff at the hotel were very obliging and friendly.
酒店的工作人员非常乐于助人且友好。
C1 verb /ˌoʊvərˈʃædoʊ/

overshadow

掩盖
Meaning
to appear more important or significant than something else, reducing its impact
Example
The scandal overshadowed his achievements.
丑闻掩盖了他的成就。
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。
B2 adjective /ˌɑːp.təˈmɪs.tɪk/

optimistic

乐观的
Meaning
hopeful and confident about the future
Example
She is optimistic about the success of her new project.
她对新项目的成功持乐观态度。
B1 noun /əˈkeɪ.ʒən/

Occasion

场合; 特殊事件
Meaning
a particular time or instance of an event; a special celebration
Example
Their wedding was a joyous occasion.
他们的婚礼是一个喜庆的场合。
B2 noun /ˈaʊtlʊk/

outlook

前景, 预测
Meaning
a person's general attitude or view; a forecast or prospect
Example
The economic outlook for the year is positive.
今年的经济前景是积极的。
C1 noun /oʊˈveɪʃən/

ovation

掌声
Meaning
an enthusiastic show of approval, especially by clapping hands
Example
The actor received a standing ovation after his performance.
演员在表演后收到了站立的掌声。
C2 adjective /ˈoʊdiəs/

odious

可憎的
Meaning
extremely unpleasant or repulsive
Example
The dictator was remembered for his odious crimes.
这位独裁者因他可憎的罪行而被记住。
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。
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。
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。
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。
C1 noun /ˈoʊvərˌsiːər/

overseer

监督员
Meaning
a person who supervises work or workers; a manager
Example
The overseer made sure the workers followed safety rules.
监督员确保工人遵守安全规则。
C1 noun /əbˈstrʌkʃən/

obstruction

障碍
Meaning
Something that blocks or gets in the way; the action of obstructing.
Example
There was an obstruction on the railway track.
铁路上有一个障碍。
B2 noun /ˈaʊtbɜːrst/

outburst

情感或活动的突然爆发
Meaning
a sudden release of strong emotion or activity
Example
She had an angry outburst during the meeting.
她在会议期间突然发火。
B2 verb /ˌoʊvərˈlʊk/

overlook

忽略
Meaning
to fail to notice or consider something; to have a view from above
Example
It's easy to overlook small details when you're in a hurry.
当你赶时间时，很容易忽略小细节。
C2 noun /ɔːrˈθɑːɡrəfi/

orthography

拼写法
Meaning
The conventional spelling system of a language.
Example
English orthography can be confusing for learners.
英语的拼写法对学习者来说可能是令人困惑的。
C2 noun /ˈɔːrɪndʒfɪn ˈleɪbiːoʊ/

Orangefin labeo

橙鳍鲤
Meaning
a freshwater fish species native to South Asian rivers, commonly found in Bangladesh and India
Example
The orangefin labeo is an important food fish in Bangladesh.
橙鳍鲤是孟加拉国重要的食用鱼。
C1 verb /əbˈsɛs/

obsess

Meaning
To preoccupy or fill the mind of someone continually and to an excessive degree.
Example
She tends to obsess over small details.
C2 noun /əbˈstɛtrɪks/

obstetrics

产科
Meaning
The branch of medicine dealing with childbirth and care of women giving birth.
Example
She is studying obstetrics to become a specialist in childbirth.
她正在学习产科，想成为一名分娩专家。
C2 adjective /ɒmˈnɪʃ.ənt/

Omniscient

全知的
Meaning
having complete knowledge; all-knowing
Example
The narrator in the novel appears to be omniscient, knowing every character's thoughts.
小说中的叙述者似乎是全知的，知道每个角色的思想。
A1 conjunction /ɔːr/

or

或
Meaning
used to link alternatives
Example
You can have tea or coffee.
你可以喝茶或咖啡。
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。
B1 adjective /əˈfɪʃəl/

official

官方
Meaning
relating to or connected with an authority or public office
Example
He is the official spokesperson for the company.
他是公司的官方发言人。
C1 noun /oʊˈmɪʃ.ən/

Omission

省略; 排除
Meaning
the action of excluding or leaving out someone or something; a failure to include
Example
The omission of his name from the list was intentional.
从列表中省略他的名字是故意的。
C1 adjective /ˈɔːrdɪnəl/

ordinal

序数
Meaning
Relating to the order or position of something in a sequence (first, second, third, etc.).
Example
The ordinal number 'third' indicates position in a sequence.
序数词'第三'表示在顺序中的位置。