on the block . for sale出售

The vacant house was on the block．这幢空房子待售。

There I saw a lot of old furniture on the block．我看见那儿有许多旧家俱在拍卖。

on the board . being discussed at the meeting在会上讨论

The rules and regulations will be laid on the board．这些规章制度将在会上讨论。

on the button . at the right place；at the heart of the matter准确；中肯

His criticisms of our work were right on the button．他对我们工作的批评是很中肯的。

on the button . exactly on time准时

She then strolled over to the department store at five o'clock on the button．她后来五点钟准时走到了百货商店。

 on the cards . probable可能的

They say war's on the cards．他们说有可能爆发战争。

It is quite on the cards that some message may come during the day．今天很可能会有消息。

on the charge of . being accused of以…的罪名

He has been sentenced to death on the charge of murder．他以谋杀罪被判死刑。

on the chance of . in the hope of怀着…的希望

We went to the cinema on the chance of seeing him there．我们去电影院希望在那儿能见到他。

People will gather by hundreds outside a police court on the chance of catching a glimpse of the criminal．数以百计的人聚在警署外希望看一眼罪犯。

 on the contrary . exactly the opposite相反地

He is not selfish；on the contrary，he is very noble and generous．他并不自私，恰恰相反，他是一个非常高尚而又慷慨的人。

The teacher thought that the children went to the zoo； on the contrary，they went to the bakery． 老师以为孩子们去了动物园，恰恰相反，他们却去了面包房。

on the cuff . agreeing to pay later； on credit以赊帐方式

He was able to buy it on the cuff．他能以赊帐方式把它买到手。

Many people buy cars and TV sets on the cuff．许多人分期付款买汽车和电视机。

on the edge of . on the verge of在…边缘

Don't put the glass on the edge of the table．不要把玻璃杯放在桌边上。

on the edge of . near；close to快要

He is on the edge of bankruptcy．他濒临破产。

Worn out， he was already on the edge of sleep．他累极了，快要睡着了。

on the eve of . just before前夕

He died on the eve of victory．他在胜利前夕死去。

The doctor told the patient that he was on the eve of complete recovery．医生告诉病人他快痊愈了。

on the face of it . apparently；as it seems从表面上看；显然地

His statement that he is a millionaire is， on the face of it，false．他说他是个百万富翁显然是虚构的。

On the face of it， his theory is OK，but we still have to wait and see how it works in practice．他的理论看来不错，但在实践中是否可行我们还得拭目以待。

on the fence . in doubt；undecided迟疑不决的；保持中立的

You have been on the fence for too long．It is time you made up your mind．你犹豫的时间太长了，该下决心了。

Philip used to sit on the fence before deciding which side he would be on， but he was looked down upon by others．菲利浦过去总喜欢在做决定支持哪一方之前观望，但他也总被他人瞧不起。

on the fly . in flight在空中；在飞行中

Tom was called out because the catcher caught the ball on the fly．汤姆被判出局，因为接球员接住了飞来的球。

on the fly . busy忙碌

Getting the house ready for the visitors kept Mother on the fly all day．为了把房子整理好接待客人，母亲忙碌了一整天。

The housekeeper of our school is always on the fly．学校管理员整天忙得很。

on the go . active活跃的；忙碌

Successful businessmen are on the go most of the time．成功的商人大部分时间总是忙忙碌碌的。

on the ground of for the reason以…为理由

On the ground of sufficient evidence he charged the young man with murder．他以充分的证据指控那个年轻人犯有谋杀罪。

He has expressed his desire to retire on the ground of failing health．他以体力不支为由表示希望退休。

on the increase . increasing在增加

Crime in big cities is on the increase．大城市的犯罪率在上升。

The demand for consumer goods is ever on the increase．对消费品的需求日益增长。

on the job . working工作着

Joe was on the job all the time．乔一直在工作。

He's on the job now．Could you ring him up later? 他在上班。你过会儿再打电话来好吗?

on the job .   working hard努力工作

He is promoted because he is always on the job．他得到了提升，因为他一直努力工作。

The operation was successfully performed because the surgeons were earnestly on the job．由于医生非常认真，手术做得很成功。

on the level . honest； truthful; honestly； truthfully诚实；可靠

I've known him all my life and you can believe me when I say he is on the level．我从小就认识他，我说他诚实，你完全可以相信我。

You can trust him because he always acts on the level．你可以相信他，因为他办事一向很公正。