1·It's easy, once you've got the knack.
你一旦掌握这个技能就容易了。
—— 《牛津词典》
2·I enjoyed school enormously once I'd settled in.
一旦适应了，我就非常喜欢上学了。
—— 《柯林斯英汉双解大词典》
3·Any escape, once it's detected, sets off the alarm.
逃跑一旦被侦察到，就会触发警报。
—— 《柯林斯英汉双解大词典》
4·We didn't know how we would cope once the money had gone.
一旦钱花光了，我们就不知道该怎么办了。
—— 《牛津词典》
5·If she once decides to do something, you won't change her mind.
她一旦决定干什么，谁也改变不了她的主意。
—— 《牛津词典》
1·I once met your mother.
我曾经见过你母亲。
—— 《牛津词典》
2·The arch once stood alone at the entrance to the castle.
拱门曾经孤零零地矗立在城堡的入口处。
—— 《牛津词典》
3·Chefs at the restaurant once cooked for President Kennedy.
这家饭店的厨师曾经给肯尼迪总统做过饭。
—— 《柯林斯英汉双解大词典》
4·Where Bucharest now stands, there once was a large, dense forest.
现在的布加勒斯特所在地曾经是一片茂密的大森林。
—— 《柯林斯英汉双解大词典》
5·The state's former commissioner of prisons once called Leonard the meanest man he'd ever seen.
这个州的前任监狱长曾经把伦纳德称为他所见过的最残忍的人。
—— 《柯林斯英汉双解大词典》
1·She once allowed me into her inner sanctum.
有一次她让我进入她的内室。
—— 《牛津词典》
2·He once sleepwalked to the middle of the road outside his home at 1 a.m.
他有一次凌晨1点钟梦游到了家外面的那条马路中央。
—— 《柯林斯英汉双解大词典》
3·I once carried a letter to a baron of that sort.
有一次，我送一封信给一个那样的男爵。
4·She once helped us to fix the television antenna.
有一次她帮我们修理电视机天线。
5·His uncle Tommy once took on three men together in a brawl.
他的叔叔汤米有一次和三个人打架。
1·I've only been there once.
我只去过那里一次。
—— 《牛津词典》
2·We'll only do it once— if at all.
我们就是干也只会干一次。
—— 《牛津词典》
3·I met Miquela once, briefly.
我见过蜜凯拉一次，时间很短。
—— 《柯林斯英汉双解大词典》
4·Ann turned over in her bed once more.
安在床上又翻了一次身。
—— 《柯林斯英汉双解大词典》
5·We need to settle this once and for all.
我们需要把这事一次解决。
—— 《牛津词典》
1·He visits Paris once or twice a month.
他一个月去一两次巴黎。
—— 《牛津词典》
2·We go there maybe once or twice a month.
我们每月大概去那里一到两次。
—— 《牛津词典》
3·I am to call them once I reach the airport.
我一到机场就得给他们打电话。
—— 《牛津词典》
4·I don't know her well, I've only met her once or twice.
我跟她不很熟；我只见过她一两次。
—— 《牛津词典》
5·Her nervousness quickly disappeared once she was on stage.
她一走上台紧张情绪便迅速消失了。
—— 《牛津词典》
1·He once lived in Zambia.
他曾在赞比亚生活过。
—— 《牛津词典》
2·She once ruled over a vast empire.
她曾统治过一个幅员辽阔的帝国。
—— 《牛津词典》
3·We once watched a red fox attacking a groundhog.
我们曾看见一只红狐攻击一只土拨鼠。
—— 《柯林斯英汉双解大词典》
4·I once went camping at Lake Michigan with a friend.
我曾和一个朋友去密执安湖野营。
—— 《柯林斯英汉双解大词典》
5·We once walked across the frozen pond at two in the morning.
我们曾在凌晨2点徒步横穿冰冻的池塘。
—— 《柯林斯英汉双解大词典》
1·Once displayed, you can drill down to deeper levels of detail.
一经显示，您就可以钻研到更深层次的细节。
2·Rules and regulations, once set up, should not be turned into a dead letter.
规章制度一经订立，不应成为一纸虚文。
—— 《新英汉大辞典》
3·(Note that by "read-only", we mean that once data is written to the data warehouse, that data is not modified by subsequent readers).
(请注意，这里所说的“只读”是指数据一经写入数据仓库，后续的读取者就不能修改它)。
4·Animal models showed that once these proteins are cleared from the brain, further damage can be prevented, and existing damage due to a previous stroke can be repaired.
动物模型表明，这些蛋白一经从脑中清除掉，就能阻止进一步损害，和由以前血管梗阻引起的损害也能被修复。
5·Once the infection - caused by one of the bacteria most often resistant to antibiotics - had been diagnosed, doctors put him on five different antibiotics.
一经诊断为感染(由对抗生素产生耐药性的最常见细菌之一造成的)，医生立即使用了五种不同的抗生素对他进行治疗。
1·The village was once a pirates' lair.
这个村子曾一度是海盗藏匿之处。
—— 《柯林斯英汉双解大词典》
2·Squash was once thought to offer all-round fitness.
壁球曾一度被认为可以提供全面的健康。
—— 《柯林斯英汉双解大词典》
3·Mathematics was once dubbed the handmaiden of the sciences.
数学曾一度被视为各门科学的基础。
—— 《牛津词典》
4·Rain water was once considered to be good for the complexion.
雨水曾一度被认为对肤色有益。
—— 《柯林斯英汉双解大词典》
5·He was once regarded as one of Mr. Brown's closest political advisers.
他曾一度被认为是与布朗先生关系最密切的政治顾问之一。
—— 《柯林斯英汉双解大词典》
1·Which is mostly true, but what they don't understand is that your brain is hardwired to adjust its feelings of happiness once you've reached certain goals, like getting rich.
这几乎是对的，但他们不知道的是，一但你达到了这个目标你的大脑会像硬链接线一样来判断快乐的感觉。
2·Once embedded, the code would have created a “botnet” of millions of zombie computers capable of launching all manner of scams on innocent folk—starting with gullible Facebook users themselves.
这些代码一但被植入，就会不知不觉地在普通用户的电脑上生成一张自动的“病毒网络”---首先就是易受攻击的“脸谱”用户。
3·Once we are bored, our minds begin to think freely.
一但我们感到无聊了，大脑才会开始自由自在的思考。
4·And as we all know, once cycling gets into your heart, it's not easily cured.
就像我们知道的，一但骑乘赢得你的心时，这是很难治疗痊愈的。
5·Once this scope is defined, all activities, products and services of the organization within this scope are included in the EMS.
一但确定该范围，则组织在此范围内所有的活动、产品和服务皆包括在环境管理体系内。