of necessity . necessarily ；unavoidably必然地；不可避免地
With the Spring Festival coming soon， the traffic will of necessity become heavier．随着春节的到来，运输必将更加繁忙。
Being your lawyer，he will of necessity want to know all the details．作为你的律师，他当然要了解全部细节。
of no account . of no importance无关紧要
This question is of no account．这个问题不重要。
of no avail . useless； unsuccessful； in vain没有用
His sickness was treated with many medicines，but all were of no avail．他的病已用各种药治过，但都无效。
Tom's practicing was of no avail．He was sick on the day of the game．汤姆平时的练习全部泡汤了，比赛那天他病了。
Although they tried hard， their efforts seemed to be of no avail．虽说他们花了很大力气，但看来还是徒劳无功。
of old . long ago； in the past古时候；过去
Knights of old had to wear armor in battle．古代的骑士作战时都戴盔甲。
Things are very different now from what they used to be of old．现在的情况跟从前大不一样了。
He often recollects days of old．他常常回想起往昔的日子。
In days of old， Mary's grandfather lived in this village．从前，玛丽的祖父就住在这个村子里。
of one's own accord . of one's own wish； voluntarily出于自愿
On her mother's birthday， Betsy did the housework of her own accord．母亲过生日那天，贝茜主动做家务。
He joined the search party of his own accord．他主动参加了搜索组。
of one's own free will . of one's own wish自动地
I'm going of my own free will；no one has ordered me to go．我是自愿去的，没有人命令我。
of sorts . not especially good勉强称得上的；普通的
Though some people praise his verse， he's really only a poet of sorts．尽管有人称赞他的诗，实际上他只是一个蹩脚的诗人。
Tom was a magician of sorts but popular at parties．汤姆算不上是个好魔术师，但在聚会时很受欢迎。
of the first water . of the finest quality； superior最好的；第一流的
He was no doubt a painter of the first water．他无疑是位一流的画家。
The jeweler chose diamonds of the first water for the queen's crown．珠宝商为王后的冠饰挑选头等钻石。
of use . useful有用的
This book will be of some use to you in future．这本书将来对你会有用的。
off and on . not regularly；occasionally时辍时续的
It rained off and on all day．雨断断续续地下了一整天。
He wrote to a girl in London off and on for several years．他与伦敦的一位姑娘断断续续地通了几年信。
We don't go to the theatre regularly，just off and on．我们不常去看戏，只是偶尔看看罢了。
off balance . not in balance失去平衡
Paul was speeding along on his bicycle，when an unexpected hole in the road caught him off balance．保尔飞快骑着自行车，没料到路上的一个坑使他失去平衡，从车上摔下来。
off balance . not prepared； not ready无准备地；不防备地
Our surprise attack caught the enemy off balance and threw them into confusion．我们的突然袭击把敌人打了个措手不及，他们顿时乱作一团。
The teacher's surprise test caught the class off balance，and nearly everyone got a poor mark．老师突然抽考，使全班毫无防备，几乎每个同学成绩都很差。
off base . not agreeing with fact； wrong与事实不符的；错误的
So far as I know， what he said at the meeting is off base．据我所知，他会上所讲的那番话与事实不符。
Any man who said such a thing is certainly off base．说这事的人都是没有根据的。
off color . unwell； in low spirits气色不好；身体有点不舒服；神情沮丧
I'm off color today．今天我感到不舒服。
“You're looking a bit off color yourself，Mr．Young．”“Oh， I feel very tired， doctor．”“杨先生，你看上去气色有点不好。”“噢，医生，我感觉很累。”
off duty . not at work不值班；下班
He is off duty today．他今天不值班。
It seems that all the taxis in New York are off duty whenever it rains．雨天，纽约所有的出租车似乎都休息了。
off guard . in a careless attitude疏忽；不提防
Tim's question caught Jones off guard．蒂姆提的问题令琼斯毫无准备。
He struck me while I was off my guard．他乘我不备打了我一下。
off somebody 's hands . done完成
The responsibility is off my hands．我已完成那项任务。
off somebody 's hands . disposed of售出
He had a lame horse which he wished to get off his hands．他有一匹瘸马要卖。
off somebody 's hands . no longer in somebody 's care or possession不再由（某人）照管或负责
Now my two sons are off my hands：one of them is working in a factory and the other teaching in a school．现在我两个儿子都自立了，一个在工厂做工，一个在学校教书。
off the beam . （of an airplane） not in the radio beam that marks the path to follow between airports（飞机）脱离航向
The pilot received a warning that his plane was flying off the beam．飞行员接到了他的飞机偏离了航向的警告。
off the beam . wrong； mistaken错误的
I've come to realize what I said at the meeting was off the beam．我已经认识到我在会上所讲的话是错误的。
Jim was off the beam when he said that the girls didn't like him．杰姆说那些女孩都不喜欢他，他是错了。