once /wʌns/ CET4

• ADV If something happens once, it happens one time only. 一次 [ADV with v]

  例: I met Miquela once, briefly.

  我见过蜜凯拉一次，时间很短。

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

  自那晚之后，我再也没睡过一次囫囵觉。

  PRON Once is also a pronoun. 一次 ['the/this' PRON]

  例: "Have they been to visit you yet?"－"Just the once, yeah."

  “他们已经去看过你了吗？”－ “来过，就那一次。”

• ADV You use once with "a" and words like "day," "week," and "month" to indicate that something happens regularly, one time in each day, week, or month. 每隔…一次 [ADV 'a' n]

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

  肺细胞约每周死亡、更新一次。

• ADV If something was once true, it was true at some time in the past, but is no longer true. 从前

  例: Her parents once ran a store.

  她父母从前开过一家商店。

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

  我从前自己住在那儿，没结婚前。

• ADV If someone once did something, they did it at some time in the past. 曾经 [ADV with v]

  例: I once went camping at Lake Michigan with a friend.

  我曾和一个朋友去密执安湖野营。

  例: 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。

• CONJ If something happens once another thing has happened, it happens immediately afterward. 一…就

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

  他读完一份市场调研报告后，10秒钟就做出了决定。

• PHRASE If something happens all at once, it happens suddenly, often when you are not expecting it to happen. 突然

  例: All at once there was someone knocking on the door.

  突然有人敲门。

• PHRASE If you do something at once, you do it immediately. 立刻

  例: I have to go at once.

  我得马上走。

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

  从火上端下来，加入香芹，搅拌后立刻上桌。

• PHRASE If a number of different things happen at once or all at once, they all happen at the same time. 同时

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

  你不能同时做两件事。

• PHRASE For once is used to emphasize that something happens on this particular occasion, that it has never happened before, and may never happen again. 就此一次 [emphasis]

  例: For once, Dad is not complaining.

  就这一次，爸爸没有抱怨。

• PHRASE If something happens once again or once more, it happens again. 再一次

  例: Amy picked up the hairbrush and brushed her hair once more.

  艾米拿起梳子，又梳了一遍头发。

• PHRASE If something happens once and for all, it happens completely or finally. 最终地 [emphasis]

  例: We have to resolve this matter once and for all.

  我们必须彻底解决这件事情。

• PHRASE If something happens once in a while, it happens sometimes, but not very often. 偶尔

  例: Your body, like any other machine, needs a full service once in a while.

  你的身体就像其他机器一样，偶尔也需要一次全面保养。

• PHRASE If you have done something once or twice, you have done it a few times, but not very often. 一两次; 几次

  例: I visited once or twice.

  我参观过一两次。

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

  有一两次，她捕捉到威廉眼中一闪的关注。