invaluable, valueless
invaluable a.无价的，非常宝贵的，相当于priceless。
Your help in moving the big refrigerator was invaluable.你帮忙搬那个大冰箱，你的帮助是可贵的。
valueless a.没有价值的，相当于worthless。
That bracelet is a cheap, valueless piece of jewelry.那个手镯是一件便宜的、不值钱的首饰。
jealous, envious
jealous a.妒忌的，暗含有憎恶与不好的感情。
He gets jealous when other man talks to his girlfriend.当别的男人和他的女朋友说话时间]，他会很嫉妒。
envious a.羡慕的,强调攀比心理所造成的羡慕。
He is envious of my new car and wants one like it.他很羡慕我的新车，也想要一辆同样的。
judicial, judicious
这是一组形近易混词。
judicial a.司法的，法律的，法庭的。
The judicial system settles arguments between people.司法系统解决人与人之间的争端。
judicious a.果断的，明智的，是个正式用语。
He made a judicious decision to save money for his old age.他做了一个明智的决定，要为他的晚年攒钱。
minor, inferior, secondary, subordinate
这一组形容词都有"次等"的意思。
minor a较少的，较小的，较次要的，常含有轻微的但并非不重要的意思。
We agreed on everything in the contract, even minor points.我们对合同中的一切问题，甚至是细枝末节都达成了一致。
inferior a.次等的，较劣的，差的，当"下级"讲时，强调职位的高低；当"次等"讲时，指素质、质量等的低劣。
Most wine from Switzerland is inferior to wine from France.产于瑞士的葡萄酒多数要比法国的差。
secondary a.第二等的，次要的，强调在重要性或顺序上处于第二位。
My job is of secondary importance to my health.我的工作比起身体来说不那么重要。
subordinate a.次要的，从属的，下级的，强调主次地位或支配和隶属的关系。
He was always friendly to his subordinate officers.她对下级官员一向和蔼可亲。
opt, apt
这是一对形近易混词。
opt v.选择，抉择，后接for。
She opted for a winter vacation, instead of one in summer.她选择了在冬天休假而不是夏天。
apt a.易于……的，(后接to)；恰当的，贴切的。
She is apt to make mistakes if you pressure her too much.如果你给她施加的压力过大，她就很容易出错。
rational, reasonable
rational a.理性的，区别于无理性；理智的，区别于感情用事的。
The rational thing to do was to take the sick man to a doctor.理智的做法是送病人去看医生。
reasonable a.有道理的，公平合理的，或指人讲道理的。
That man works very hard, so it is reasonable for him to ask for more money.那个人工作努力，所以他要求加薪是合情合理的。
refrain, restrain, constrain
refrain v.抑制，禁止，强调抑制一种冲动，是正式用语，为不及物动词，后接介词from。
Students refrain from smoking in the classroom.学生们克制住不在教师抽烟。
restrain v.抑制，约束，指通过管束阻止某事发生，是及物动词，其习惯用法是restrain sb. (sth.) from doing。
She restrains her dog by walking him on a leash.溜狗时，她牵着狗来限制它的活动。
constrain v.强迫，力劝，是及物动词。
A law constrains the government from spending more money than it takes in.法律限制政府开支大于收入。
respectable, respectful, respective
这是一组形近易混词。
respectable a.值得尊敬的，有好名声的。
They are respectable people who are liked and trusted in their town.他们在家乡是受人们敬爱和信任的人。
respectful a.尊敬他人的，恭敬的。
Students and teachers should have a respectful attitude toward each other.师生应该相互彬彬有礼。
respective a.单个的，分别的。
revolve, evolve, involve
revolve v.旋转，转动。
The room began to revolve , then he fainted.屋子开始旋转，然后他就昏倒了。
evolve v.发展，演变。
Agriculture evolved slowly over thousands of years.几千年来，农业发展得很缓慢。
involve v.需要，包含；使卷入，牵涉。
Getting a driver's licence involves learning how to drive, studying the rules of the road, and taking a test.要得到驾驶执照需要学习开车，学习交通规则，还要经过考试。
sanction, sanitation
sanction n.认可，准许，批准。
I need my parents' sanction to stay out late.我晚回家需要得到父母的批准。
sanitation n.公共卫生，环境卫生，卫生设备。
Strict sanitation is used in businesses such as barber shops and restaurants.在理发店和餐馆等营业场所执行严格的公共卫生制度。
scenery, scene, view, landscape
这一组名词都有"景色"的意思。
scenery n.风景，景色，舞台布景，强调从美的角度看，某个国家或地区的总体外貌。
Each year, we spend our vacation in the mountains and enjoy the scenery.我们每年到山区渡假，并欣赏那里的风景。
scene n.指从远处看到的某一具体景色、景象，也可以指人物的活动场面；(犯罪的)地点，现场。
They stood gazing the happy scene of children playing in the park.他们站在那里，注视着孩子们在公园里玩耍的场景。
view n.指从远处或窗户看到的视野范围内的风景；观点，看法。
Our house has a view of the park.我们的房子可以看到公园的景色。
landscape n. (自然的)风景，景色；风景画。
The landscape seen from the mountains is green and beautiful.站在群山之巅看到的是一片美丽的绿色。
sensible, sensitive, sentimental, sensational
这是一组形近易混词。
sensible a.有知觉的，可感知的；明智的。
The patient was speechless but still sensible.病人虽然不能说话但仍然有知觉。
sensitive a.敏感的，灵敏的。
This film is sensitive to light.这种胶片对光很敏感。
sentimental a.多愁善感的，感伤的。
The novel has scenes full of love and loss; it is so sentimental!小说有多处场景充满爱情的悲欢离合，真是感伤啊！
sensational a.耸人听闻的，令人激动的。
I read a sensational story about a ten-year-old mother.我听到一则耸人听闻的故事：十岁女孩做妈妈。
technological, technical
这是一组形近易混词。
technological a.技术上的。
a major technological breakthrough主要技术性突破
technical a.技术的，工艺(学)的；专门的，深奥的。The banker made some technical points about the economy in his speech.银行家在他的关于经济的演说中提出了几个很专业的论点。
transaction, transition, transmission, transformation, transfer
这是一组在考研和CET-6中经常出现的形近易混词。
transaction n.交易行为，处理。
Transactions of shares on the stock exchange were up today.今天证券交易所的股票成交额上升了。
transition n. (从一种情况到另一种的)过渡，更替。
The transition from high school to college can be difficult for students.对于学生来说，从中学到大学的过渡会是困难的。
transmission n.传播(比如疾病)；广播。
The transmission of germs can occur by contact, breathing, and eating.细菌通过接触、呼吸和饮食传播。
transformation n. (外观或性质的)改变，改观，转变。
His character seems to have undergone a complete transformation since his marrige.他结婚之后性格判若两人。
transfer n.转移，转让；(工作的)调动；(旅途中的)换乘，改变路线。
The club's goalkeeper isn't happy here, and has asked a transfer.这个足球俱乐部的守门员在此过得不愉快，已经要求转会到其他俱乐部。