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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。
C1 noun ɔːrˈdiːl

ordeal

艰难的考验
Meaning
A physical or mental painful experience that must be endured
Example
Surviving the wilderness was a tough ordeal for them.
在野外生存对他们来说是一场艰难的考验。
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 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。
C2 noun /oʊd/

ode

颂诗
Meaning
a lyrical poem, often expressing praise or strong emotions
Example
The poet wrote an ode to the beauty of nature.
诗人写了一首歌颂自然美的颂诗。
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。
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 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 /ˈɒrɪz(ə)n/

orison

祷告
Meaning
a prayer, especially a devout or formal one
Example
He whispered a quiet orison before going to sleep.
他在睡觉前低声祈祷。
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 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。
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。
B2 verb /ˌoʊvərˈpeɪ/

overpay

支付过多
Meaning
To pay more than is necessary or reasonable.
Example
She realized she had overpaid for the concert tickets.
她意识到她为音乐会门票支付过多。
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。
A2 noun /ˈʌn.jən/

Onion

洋葱
Meaning
a round vegetable with a strong taste and smell, made up of many layers
Example
I need to chop some onions for the curry recipe.
我需要切一些洋葱来做咖喱菜谱。
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 /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 /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。
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。
C2 adjective /ˈɒkjʊlər/

ocular

眼科的
Meaning
Relating to the eye or vision.
Example
The patient was referred to a specialist for ocular treatment.
患者被转诊到眼科专家进行治疗。
A1 preposition, adverb /ˈoʊvər/

over

在…上面
Meaning
across, on top of, or beyond
Example
The book is lying over the table.
书在桌子上面。
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 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。
B2 noun /ˈɔːɡən/

organ

器官
Meaning
a part of the body that performs a specific function
Example
The heart is an important organ in the human body.
心脏是人体重要的器官。
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。
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。
B2 adjective ɔːrˈɡæn.ɪk

organic

有机的
Meaning
Produced or involving production without the use of chemical fertilizers, pesticides, or other artificial agents.
Example
Organic farming improves soil health and reduces pollution.
有机农业改善土壤健康并减少污染。
A1 adverb /ɔːf/

off

关
Meaning
away from a place, position, or time; not functioning
Example
He turned off the light before leaving the room.
他在离开房间之前关掉了灯。
C2 noun /ˈəʊpəs/

opus

创作作品
Meaning
A creative work, especially a large and important piece of music or art.
Example
The composer considered the symphony his greatest opus.
作曲家认为交响曲是他最大的创作作品。
B2 adverb /ˈɒdli/

oddly

奇怪地
Meaning
in a strange or unusual way; unexpectedly
Example
Oddly, he didn’t seem upset by the bad news.
奇怪的是，他似乎并没有因为坏消息而难过。
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。
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。
B2 adjective; verb (past participle) /ˈɒkjʊpaɪd/

occupied

被占用的；被占领的
Meaning
being in use or taken; filled or lived in; controlled or held by force
Example
The room is occupied, so please wait outside.
房间被占用，请在外面等候。
C2 adjective /ˈɒf.biːt/

offbeat

不寻常
Meaning
Unusual, unconventional, or different from the norm.
Example
She has a very offbeat sense of humor.
她有非常不寻常的幽默感。
B1 noun ˌɔː.ɡən.aɪˈzeɪ.ʃənz

organizations

组织
Meaning
Organized groups of people with a particular purpose
Example
Organizations play a key role in policymaking.
组织在政策制定中发挥着重要作用。
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。
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。
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。
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 /ˈɔːrdʒi/

orgy

荒淫派对
Meaning
A wild party involving excessive indulgence, especially of a sexual nature.
Example
The novel described a scandalous orgy in a wealthy mansion.
小说描述了在一座富裕的豪宅里举行的丑闻般的荒淫派对。
C1 noun /ˌɒk.sɪ.dʒɪˈneɪ.ʃən/

oxygenation

供氧或氧气治疗
Meaning
The process of supplying or treating with oxygen.
Example
Deep breathing exercises improve oxygenation of the body.
深呼吸练习有助于改善身体的供氧。
C2 adjective /ɒˈstɛnsɪv/

ostensive

显性
Meaning
clearly demonstrative or pointing out; explicitly shown
Example
The teacher gave an ostensive example to clarify the concept.
老师举了一个显性的例子来阐明概念。
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。
C2 noun /ˈɒlɪv brɑːntʃ/

olive-branch

橄榄枝
Meaning
A symbol of peace or reconciliation; an offer to end conflict.
Example
He extended an olive-branch to his rival after years of hostility.
他在多年敌对之后向他的对手伸出了橄榄枝。
C1 adjective /ˌɔːrnəˈmɛntl/

ornamental

装饰性的
Meaning
Serving as decoration; decorative rather than functional.
Example
The garden was filled with ornamental plants.
花园里满是装饰性的植物。
B2 adjective, verb /əbˈskjʊr/

obscure

模糊
Meaning
Not clearly expressed or understood; to make something difficult to see or understand.
Example
The meaning of the poem was obscure to most readers.
诗的意义对大多数读者来说是模糊的。
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。
C1 verb /aʊtˈwɪt/

outwit

智胜
Meaning
to defeat or gain an advantage over someone by being more clever or cunning
Example
The fox managed to outwit the hunters.
狐狸成功地智胜了猎人。
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。
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 verb /əˈkluːd/

occlude

堵塞
Meaning
To block or close up an opening or passage.
Example
The pipe was occluded by mineral deposits.
管道因矿物沉积物而被堵塞。
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。
B2 noun /ˈoʊ.dər/

Odour

气味
Meaning
a distinctive smell, especially an unpleasant one
Example
The odour of fresh bread filled the kitchen.
新鲜面包的气味充满了厨房。
A2 verb /oʊˈbeɪ/

obey

服从
Meaning
to follow orders or instructions; to comply with rules
Example
Children should obey their parents and teachers.
孩子们应该服从父母和老师的命令。
B2 noun /ˌoʊ.vɚˈkraʊ.dɪŋ/

overcrowding

过度拥挤
Meaning
Excessive crowd or packed condition, having more people or vehicles in a place than the approved capacity.
Example
The subway system suffers from severe overcrowding during peak hours.
地铁系统在高峰时段面临严重的过度拥挤。
C1 adjective /əbˈtjuːs/

Obtuse

迟钝的; 愚笨的; 理解慢
Meaning
annoyingly insensitive or slow to understand; lacking in intelligence or perception
Example
He was being deliberately obtuse about the instructions.
他故意在指令上表现得迟钝。
C1 adjective /ˌəʊvərˈstɪmjʊˌleɪtɪd/

overstimulated

过度刺激的
Meaning
Excessively excited or aroused, overwhelmed by too much stimulus.
Example
Overstimulated minds can lead to burnout and decreased productivity.
过度刺激的头脑可能导致倦怠和生产力下降。
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。
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 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 /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 noun /ˈaʊtˌskɜːrt/

outskirt

城市郊区
Meaning
the outer edge or border of a town or city
Example
They built a new factory on the outskirts of the city.
他们在城市郊区建了一家新工厂。
C2 noun ˈoʊʃən ˌstrætɪfɪˈkeɪʃən

ocean stratification

海洋分层
Meaning
The formation of layers in ocean water due to differences in density.
Example
Ocean stratification affects marine biodiversity.
海洋分层影响海洋生物多样性。
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。
C2 adjective /ˈɒfɪʃ/

offish

冷淡
Meaning
Unfriendly, distant, or reserved in manner.
Example
He seemed offish at the party and avoided most conversations.
他在派对上显得很冷淡，避开了大多数谈话。
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。
A2 modal verb /ɔːt/

ought

应该
Meaning
Used to indicate duty, correctness, or moral obligation.
Example
You ought to respect your elders.
你应该尊重长辈。
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。
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。
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。
B1 noun /ˈɑː.lɪv/

Olive

橄榄
Meaning
a small oval fruit with a hard pit, typically green or black, used for eating or making oil
Example
Olive oil is considered one of the healthiest cooking oils available.
橄榄油被认为是最健康的烹饪油之一。
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。
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。
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 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。
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。
A2 noun /ˈʌv.ən/

Oven

烤箱
Meaning
an enclosed compartment used for heating, baking, or drying food
Example
She baked cookies in the oven for thirty minutes.
她在烤箱里烤了三十分钟的饼干。
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。
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。
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。
C1 adjective /ˌɔː.riˈen.təl/

Oriental

与东亚国家相关的；东方的
Meaning
relating to the countries of East Asia; eastern
Example
The museum has a beautiful collection of oriental art.
博物馆收藏有美丽的东方艺术作品。
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 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。
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。
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。
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 noun /ˈɒt.ər/

Otter

水獺
Meaning
a mammal with webbed feet that lives near water and feeds on fish
Example
The playful otter swam gracefully in the river.
顽皮的水獺优雅地在河里游泳。
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。
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。
C1 adjective /əbˈdʒek.ʃən.ə.bəl/

Objectionable

令人反感的
Meaning
arousing distaste or opposition; unpleasant or offensive
Example
His objectionable behavior made everyone uncomfortable.
他的令人反感的行为让每个人都感到不舒服。
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 /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 adjective /əˈblɪɡ.ə.tɔː.ri/

obligatory

强制的
Meaning
Required by a legal, moral, or other rule; compulsory.
Example
Wearing a seatbelt is obligatory in most countries.
在大多数国家，系安全带是强制的。
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。
B1 adjective, adverb /ˈoʊvərɔːl/

overall

总体上
Meaning
in general or as a whole
Example
Overall, the project has been successful.
总体上，项目已成功。
A2 pronoun /aʊərˈsɛlvz/

ourselves

我们自己
Meaning
used by the speaker to refer to themselves and one or more others as the object of the verb
Example
We should help ourselves before helping others.
我们应该在帮助他人之前先帮助自己。
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.
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。
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。
C1 noun /ˈoʊ.vər spɪl/

Over-spill

溢出
Meaning
the overflow of liquid from a container; excess that cannot be contained
Example
The overspill from the river flooded nearby farms.
河水溢出导致附近的农田被淹没。
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。
C2 verb /oʊˈpaɪn/

opine

表达意见
Meaning
to express an opinion or belief
Example
The professor opined that the policy would fail.
教授认为政策会失败。
C1 noun /ˈaʊtriːtʃ/

outreach

援助扩展
Meaning
The act of providing services or support to people who might not otherwise have access to them.
Example
The charity launched a new outreach program for the homeless.
慈善机构为无家可归的人推出了一个新的援助扩展计划。
C2 adjective /ˈɒpjʊlənt/

opulent

奢华的
Meaning
Ostentatiously rich, luxurious, or lavish.
Example
They hosted an opulent wedding with gold decorations.
他们举办了一场奢华的婚礼，装饰有金色装饰品。
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。
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 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。
A1 adverb /wʌns/

Once

一次; 过去的某个时候
Meaning
one time only; at some time in the past; formerly
Example
I have been to Paris once in my life.
我一生中只去过一次巴黎。
C1 noun /ɒpˈtɒmətri/

optometry

验光学
Meaning
The practice or profession of examining the eyes and prescribing corrective lenses.
Example
She studied optometry at the university to become an eye specialist.
她在大学学习验光学，成为一名眼科专家。
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。
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 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。
C1 verb /ˈɔːstrəˌsaɪz/

ostracize

排斥
Meaning
to exclude someone from a group or society; to banish or shun
Example
After the scandal, he was ostracized by his former colleagues.
丑闻发生后，他被前同事排斥。
C2 adjective /ˈɑːbdjʊrət/

obdurate

固执
Meaning
Stubbornly refusing to change one's opinion or course of action.
Example
He remained obdurate despite everyone's pleas.
尽管大家的恳求，他依然固执。
C2 adjective /ˈoʊ.pən ˈhæn.dɪd/

Open-handed

慷慨的; 自由的
Meaning
Generous; liberal; giving freely;
Example
He is very open-handed with his money and always helps those in need.
他对自己的钱非常慷慨，总是帮助有需要的人。
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。
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。
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 noun /ɒpˈtɒmɪtrɪst/

optometrist

眼科验光师
Meaning
A healthcare professional who examines eyes and prescribes corrective lenses.
Example
The optometrist prescribed new glasses for her.
眼科验光师为她开了新的眼镜。
A2 adverb /ˈɒbviəsli/

obviously

显然
Meaning
in a way that is easily perceived or understood; clearly
Example
Obviously, he didn’t read the instructions.
显然，他没有读说明书。
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。