dam up . seal with a dam；hold back by means of a dam 筑坝拦水

They have dammed up the valley and built a reservoir．他们已经在山谷里筑了坝，建造了水库。

dam up .hold back；restrain（a feeling，etc．）抑制（感情等）

She not only did her best to dam up her sorrows，but went in for her work even more energetically than ever before．她不仅竭力抑制内心的悲痛，而且以更加充沛的精力投入了工作。

He dammed up his fury until he could no longer remain silent．他一直到忍无可忍时才大发雷霆。

We should do our best to dam up inflation．我们应尽一切努力来制止通货膨涨。

damp down . make（a fire）burn more slowly 减弱（火势）

She damped the fire down for the night．她把炉火封上过夜。

damp down . make sad or dull 使沮丧；使扫兴

Nothing could damp down his spirits．任何事情都不能破坏他的兴致。

Difficulties and failures did not damp down his enthusiasm．困难和失败都没有挫伤他的积极性。

damp down . diminish 减少；缩小

Inflation is being damped down．通货膨涨的势头正在被抑制。

dash down . throw down violently 猛摔

He dashed the cup down in his anger．他一怒之下摔了茶杯。

dash down . move quickly down or along 沿着…飞奔

The horses dashed down the hill．这些马从山上飞奔而下。

dash off . hurry away；rush off violently匆匆离去；猛冲而去

He has dashed off to London on an urgent business．他因急事匆忙赶往伦敦去了。

I must dash off now．我必须立刻离开。

dash off . write or draw very quickly 匆忙完成；草就

He dashed off the article before supper．他在晚饭前匆忙完成了这篇文章。

I just dash off a letter to him．我要给他赶写一封信。

date from . date back to . have existed since；go back to；trace back to 始于（某一历史时期）；源于；追溯到

Insurance dates from the seventeenth century．保险始于十七世纪。

The castle dates back to the fourteenth century．这城堡建于十七世纪。

The custom dates back to the time of the Roman Empire．这种风俗可以回溯到古罗马时期。

The traditional friendship between our two peoples dates back to ancient days．我们两国人民之间的传统友谊可以追溯到遥远的过去。

date from .  be addressed from a place（信）由某处寄出

The letter dates from New York．这封信是从纽约寄来的。

dawn on . dawn upon . become gradually known to 逐渐明白

It dawned upon us that he was unwilling to help．我们逐渐明白了，他是不愿意帮助的。

It suddenly dawned on her that her youth was gone．她突然意识到，自己的青春时光已经一去不复返了。

The truth finally dawned on him．他终于开始明白事情真相了。

The idea suddenly dawned upon me．我突然想到了那个念头。

day after day . every day 日复一日；每天

He has to work from morning till night day after day．他每天不得不从早干到晚。

day by day .  一天天地

Day by day，he seems to grow a little stronger．他似乎一天一天地长强壮起来了。

The weather is getting warmer and warmer day by day．天气一天一天地变暖和了。

day in and day out . day after day；continuously 日复一日地；每天

Day in and day out he gave the same excuse for his laziness．他日复一日地以同样的借口为他的懒惰开脱。

I dislike my neighbors because day in and day out they play their stereo loudly．我不喜欢我的邻居，因为他们每天把音响开得声音很大。

He always works day in and day out in one week，so Sundays are the only free days he has．他一周内不停地工作，因此只有星期日才有空。

deal in . trade in；buy and sell 做买卖

The new shop deals in woolen goods．这家新商店经营毛织品。

The garage deals in gasoline，machine oil，tires，etc．这家汽车修理厂经销汽油、机油和车胎等商品。

deal in . be engaged in；be busy with 从事；忙于

She deals in foreign affairs．她从事外交活动。

She deals in gossip and slander．她常搬弄是非和造谣中伤。

deal with . treat；take actions about；be concerned with 处理；对付；论述；涉及

The man is hard to deal with．这个人很难对付。

It is becoming increasingly difficult to deal with the problems of traffic in big cities．对付大城市的交通问题变得日益困难。

His latest work deals with the Second World War．他的新书的内容是关于第二次世界大战。

deal with . have a relationship with somebody ，in business matters 与…有来往；与…有生意来往

He has been dealing with this shop for twenty years．他同这家商店打了二十年交道。

decide against . make a decision not in favour of 决定不

I have decided against going far away in summer vacation．暑假我决定不出远门。

The government has decided against increasing taxes．政府决定不增加税款。

The court decided the case against the plaintiff．那法院的判决对原告不利。