To spread out; unfold
展开；摊开
A green valley opened up before us.
青翠的山谷展现在我们眼前
To begin operation
开战；开火
The new store opens up next month.
这家新商店将在下个月开张
The artillery opened up at dawn.
炮兵于拂晓时开口
&I{Informal} To speak freely and candidly
【非正式用语】 直言不讳
At last the frightened witness opened up and told the truth.
这名吓坏了的目击者终于直言不讳说出了事实
To make an opening in by cutting
切开
The surgeon opened up the patient's chest.
这名外科医生切开了病人的胸部
To make available or accessible
使可利用；使通往
open up new markets.
打开了新的市场
&I{Informal} To accelerate. Used of a motor vehicle.
【非正式用语】 （用于汽车）加速
speak frankly to; conceal nothing from
坦率直言
I had always been completely open with my mother.
我一直在妈妈面前知无不言。
out of doors; not under cover
户外
in a court of law, before the judge and the public
在法庭上（面对法官和群众）
(of a case or argument) admitting no doubt or dispute; straightforward
（案件或争论）一目了然的
(Cricket)play as one of the pair of batsmen who begin a side's innings
(板球)开球
fully aware of the risks and other implications of an action or situation
睁大眼睛（充分认识到风险）
I went into the job with my eyes open—everyone knows what happens to an unsuccessful manager.
我睁大眼睛开始了工作——每个人都知道失败的经理会有什么下场。
I went into the job with my eyes open—everyone knows what happens to an unsuccessful manager.
我睁大眼睛开始了工作——每个人都知道失败的经理会有什么下场。
accelerate a motor vehicle
加速（机车）
(of a sports player or team) create an advantage for one's side
（运动员，运动队）取得本方的领先
he opened up a lead of 14–8.
他开了个好头，以14比8领先。
To begin firing on.
开火
To become aware of the truth of a situation.
使看清事实真相