请看台词：
I hear your specialty is investigating infidelity.
It's my bread and butter.
听说你专门调查出轨事件。
这是我的谋生之道。
1.bread and butter
黄油面包是西方人日常生活中不可或缺的主食，因此被用来喻指：生计；谋生之道；主要收入来源，职业,主业，饭碗，靠山，(某人或公司的)主要收入来源；永不分离的关系（搭配）
Something that is the bread and butter of a person or organization is the activity or work that provides the main part of their income.
在某种微妙之处如同：meal ticket；又像汉语里“饭碗”。
I've got a new job. It's my bread and butter from now on.
我找到了个新工作。从现在开始。它就是我的饭碗了。
I can't play hooky from work. That's my bread and butter.
我不能旷工，那可是我的饭碗。
据《美国地域英语词典》(The Dictionary of American Regional English)记载，bread and butter是两个人一起走路忽然被别人或某件东西分开时所使用的感叹词。如果一对情侣在林荫道上携手漫步，突然一个莽撞的小孩从他们中间跑过去，冲散了二人，那女友可能就会娇嗔地要求男友:“快说 bread and butter!”这句简单的补救语也许蕴含着这样的祈望:“我们会像面包加黄油那样永不分离。”
Bread and butter is aic combination.
面包和黄油是一个经典的搭配。
As ever, politics, vulgarity and sentimentality were the bread and butter of the Academy Awards.
政治、粗鄙和感伤一度成为奥斯卡奖的支柱。
《新闻周刊》评论家大卫·安(David An sen )语。
Drawing is my bread and butter.
画画是我谋生的手段。
How does he earn his bread and butter?
他怎样谋生的呢？
Our customers are our bread and butter, so treat them with respect.
我们的客户是我们的收入来源（衣食父母），所以要尊重他们。
In my book, I assumed that writing was her bread and butter, but she told me that it's kind of a hobby.
我以为她以写东西为生，但她却告诉你这只是她的一个爱好。
The mobile phone business was actually his bread and butter.
移动电话业务实际上是他的主业。
I can't give up the job, for it's my bread and butter.
我不能放弃这工作，因为那是我的饭碗。
Teaching English is my bread and butter.
教英语使我的职业
Social media—Facebook’s bread and butter—are likewise in rivals’ sights.
《经济学人》
社交媒体——脸书的主要收入来源——同样受到竞争对手的关注。
Teaching is her bread and butter. She earns her living by working as a teacher.
教学是她的主要收入来源。她靠当教师谋生。
Photography started as a hobby for him, but now it has become his bread and butter.
摄影起初是他的爱好，但现在它成了他的主要收入来源。
The real estate business has always been their bread and butter. It's how they make a living.
房地产生意一直都是他们的经济支柱，是他们的生计来源。
Writing articles for magazines is her bread and butter. It's how she pays her bills.
为杂志写文章是她的主要收入来源。这是她支付账单的途径。
Photography assignments are his bread and butter. They provide him with the majority of his income.
摄影任务是他的主要收入来源。它们占了他大部分的收入。
Real estate sales are their bread and butter. That's how they make most of their money.
房地产销售是他们的主要收入来源。这是他们大部分收入的来源。
Freelancing as a graphic designer is my bread and butter. It's my primary source of income.
作为一名自由职业的平面设计师是我的主要收入来源。这是我主要的经济来源。
2.bread-and-butter 用连字符连起来，变成了形容词，指：最基本的；很重要的；生计的；最实用的
basic; very important
比如：
a bread-and butter issue 最基本的问题
a bread-and-butter job.
一份糊口的工作
bread-and-butter work赖以养家糊口的工作
a bread-and-butter note.
一封感谢款待的短笺
住房、医疗、教育都可以称作bread-and butter issues。
The opposition gained support by concentrating on bread-and-butter matters.
反对党关注与大多数人切身利益相关的问题，从而赢得了人们的支持。
Household appliances are the company's bread-and-butter goods.
家庭用具是这家公司的主要商品。
She worries about everything, even the bread-and-butter tasks of everyday life.
她什么都担心，甚至是日常生活的基本任务。
3.infidelity 指不忠，出轨。反义词fidelity 则表示忠诚。
She could not forgive his infidelities.
她无法原谅他的不忠行为。
George ignored his partner's infidelities.
乔治对伴侣的不忠行为视而不见。
The ultimate sin was not infidelity, but public mention which led to scandal.
最大的罪过不是通奸而是公众议论，是它导致了丑闻的发生。
The implication that marital infidelity enhances a leader's credibility is preposterous.
婚姻不忠会提升领导人可信度的暗示荒谬之极。
I divorced him for infidelity.
我因他的不忠而与他离婚。
He seemed more amazed at his wife's infidelity than angry.
他对妻子的不贞与其说感到愤怒，不如说感到惊愕。
