keep under observation . watch 注视

The police keep all habitual criminals under observation from the day they leave the prison．所有惯犯自出狱那天警察就密切注视他们。

keep under observation . watch or study attentively 注意观察；研究

The doctor cannot understand Jane's stomach trouble，and he wants to keep her under observation for a few days．大夫搞不清简的胃有什么毛病，于是想把她留在医院里观察几天。

keep under one's hat  . keep secret 保密

If I tell you the date of the election，can you keep it under your hat? 假如我把选举日期告诉你，你能对此保密吗?

I have won the contract for the new tax computer，but keep it under your hat until it is announced officially．我们已经赢得了这份新型税务计算机的合同，但在正式宣布之前还要保密。

Mr．Jones knew who had won the contest，but he kept it under his hat until it was announced publicly．琼斯先生早已知道谁在这次比赛中获胜，但他保守秘密直到正式宣布为止。

keep up . remain at a high level居高不下；不低落

Prices have kept up all the year．全年物价一直居高不下。

So long as the cost of raw materials keeps up，  . the prices of consumer goods will keep up，too．只要原材料成本不下降，消费品价格也不会下降。

keep up . maintain or continue the same speed or level；not fall behind继续；保持某一速度和某一水平；不落后

If we can keep up this speed，we should arrive there in about two days．如果我们能保持这个速度，我们在两天之内就应到达那里。

That student has been getting all A's．I hope he can keep it up．那个学生各门功课都得了A，我希望他能保持下去。

Bill had to word hard to keep up．比尔得努力才不落后。

The younger boys were not able to keep up in the race．年轻一些的小伙子们在赛跑中没能跟得上。

In spite of the unfavourable weather，the grain output of the province managed to keep up．尽管天气不好，这个省的粮食产量并未下降。

keep up . maintain in good condition or repair 保存：继续保持良好状况

Mr．Smith was too poor to keep up his house．史密斯先生太穷了，修不起房子。

The cottage was so old that it was very difficult to keep up．这农舍太破旧了，很难再维持下去。

The city government provides the funds to keep up the roads and other public facilities．市政府提供资金维修道路和其它公共设施。

keep up . （spirits，courage，morale，strength，determination，）stay buoyant，bright（精神、勇气、情绪、体力、决心等）保持愉快、活泼、开朗

Keep up your courage！鼓起勇气，不要气馁。

Their spirits kept up well in spite of hardships．虽然很艰苦，但他们精神很饱满。

Her spirits have kept up very well，despite all her bad luck．尽管她遭到厄运，她的情绪一直很高。

The troops' spirits were kept up by the occasional visit of well-known entertainers to their camps．由于著名的文娱节目表演者常来到军营演出，部队的士气很高涨。

To keep your strength up，eat well and get enough sleep．要保持体力，就要吃饱睡足。

keep up . prevent from sinking or falling；support 使浮起；支撑不倒

The life preserver kept him up until the boat came．救生衣使他保持浮在水面直到小船来救他。

The surviving sailors managed to keep up for several hours and were eventually picked up by a lifeboat．这位幸存的船员努力支撑着使自己浮在水面，最后终于被一艘救生艇救起。

Those houses are so badly built that we wonder how they keep up in a strong wind．这些房子建造得太差劲，我们怀疑它们怎么能经受得住大风暴的袭击。

keep up . maintain friendship or correspondence保持友谊或通讯关系

I've kept up friendship with him for twenty years．我和他二十年来一直保持着友好关系。

I keep up correspondence with my college friends．我一直跟我大学时代的朋友通信。

keep up . （storm，sunshine，rain，）go on；not stop；continue继续

The rain kept up for two days and the roads were flooded．雨持续下了两天，路面已积水成灾。

If this storm keeps up，the crops will be destroyed．这场风暴要是持续不停，庄稼就要被毁了。

I hope the weather will keep up．我希望这天气晴朗下去。

 

 

keep up . keep informed 知悉

Mary is interested in politics and always keeps up with the news．玛丽对政治很感兴趣，对新闻总是知道得很多。

keep up . prevent from going to bed at the usual time 影响某人在正常时间去睡觉

“Good heavens！It is nearly half past midnight．I must go and I do hope I haven't kept you up．”“天哪！快半夜了，我得走了，但愿没有影响你休息。”

You shouldn't keep your guests up talking for so long．你不该不让客人睡觉陪你谈这么长时间。

keep up . continue to practise，observe；not allow to lapse or be neglected （the old customs，tradition，）继续保存（习俗、传统等）；不允许生疏或忽视

Although the children know all about the myth of Father Christmas，they still like to keep up the old Christmas customs．尽管孩子们知道圣诞老人的秘密，但他们还是喜欢保持圣诞节的这种风俗习惯。

If only I'd kept up my German，I might have got that job in Berlin．要是我没有把德语荒疏就好了，否则我就会得到那份在柏林的工作了。

11．prevent from falling；stay in position 使不掉下来；使保持在适当的位置上

Some boys wear suspenders to keep their trousers up．有些男孩使用吊带来吊住裤子。

keep up . （efforts，good work，payments，rent） maintain or continue with regularity 继续定期（努力、付款、付租金等）

If you don't keep up the payments，I'm afraid the company will take possession of you car．如果你不能定期付款的话，恐怕公司就要收回你的车子了。