We once walked across London at two in the morning...

Earrings need to be taken out and cleaned once in a while.

耳环要偶尔取出来清洗一下。

You can't be doing two things at once...

不能一心二用。

I feel terribly sleepy all at once...

我突然觉得特别困。

For once, dad is not complaining...

爸爸这次破天荒地没有抱怨。

Remove from the heat, add the parsley, toss and serve at once...

端离炉子，加上欧芹，颠起翻面后就立刻上桌。

The patient was seen for follow-up visits once every three months...

这位病人每三个月接受一次随访就诊。

Lung cells die and are replaced about once a week...

肺细胞约每周新老更替一次。

'Once upon a time,' he began, 'there was a man who had everything.'...

“很久很久以前，”他开始说道，“有这么一个人，他应有尽有。”

My daughter comes to visit me once every fortnight.

我女儿每两周来看我一次。

The decision had taken about 10 seconds once he'd read a market research study...

在他看过一份市场调研报告后大概10秒钟就作出了决定。

Since that evening I haven't once slept through the night...

从那天晚上之后，我没有睡过一次安稳觉。

No bank could ever pay off its creditors if they all demanded their money at once...

如果所有的储户同时要求提取存款，没有哪家银行能办得到。

I met Wilma once, briefly...

我曾经和威尔玛有过短短的一面之缘。

Amy picked up the hairbrush and smoothed her hair once more...

埃米拿起发梳，再次将头发梳理整齐。

I lived there once myself, before I got married...

我结婚前曾独自在那儿住过。

I once went camping at Lake Darling with a friend...

我曾和一位朋友在达令湖畔露营。

Once customers come to rely on these systems they almost never take their business elsewhere...

顾客一旦依赖上这些系统，几乎就不会光顾其他商家。

Once or twice she had caught a flash of interest in William's eyes...

有那么一两次，她发现威廉的眼睛里流露出一丝感兴趣的神色。

I popped my head round the door once or twice...

我有几次头撞到了门上。

Once again an official inquiry has spoken of weak management and ill-trained workers.

官方调查又一次提到了管理不力与工人缺乏训练的问题。