at once

1. She knew at once that he was concealing something from her.
   她马上知道了他有事瞒着她。
2. I dreamed up a plan to solve both problems at once
   我想出了一个方案，可以同时解决两个问题。
3. The place at once enraptured me
   那个地方一下子把我迷住了。
4. If they'd operated and pinned her arm at once, she might have healed by now
   如果他们当时马上就给她的胳膊做手术并用钢针固定，她现在可能已经痊愈了。
5. I must speak to Tania at once
   我要马上跟塔尼娅讲话。
6. I feel terribly sleepy all at once
   我突然觉得特别困。
7. I have to go, I really must, at once
   我得走了，我真的必须马上就走。
8. The audience at once greeted him warmly.
   观众立即对他作出了热情的反应。
9. The receptionist recognized him at once
   接待员一眼就认出他了。
10. All at once, Mick's serious expression softened into a grin
    米克严肃的表情一下子变成了笑脸。
11. She says she must speak with you at once
    她说她必须立刻跟你谈谈。
12. I wrote back to Meudon at once to fix up a meeting.
    我马上给缪顿回信安排会面。
13. Here we are; let's get off at once.
    到站了，快下去。
14. The tired traveller fell back on the bed and at once fell asleep.
    那个疲劳的旅客往床上一倒就睡着了。
15. The murderer was at once apprehended.
    凶犯立即被拘捕了。
16. If anything happens to him, let me know at once.
    如果他出了什么事，请立刻通知我。
17. In case you give me leave, I will start at once.
    如果你许可，我立即就动身。
18. I recognized his voice at once.
    我立刻听出了他的口音。
19. When a mistake is discovered, it should be corrected at once.
    发现错误应立即纠正。
20. We advise that steps be taken at once.
    我们建议立即采取措施。
21. I must be going back at once.
    我得马上回去。
22. We must start at once.
    我们必须马上出发。
23. All at once I fell into a state of profound melancholy.
    我立即陷入无限的愁思之中。
24. After the theatre let out, the street was at once thronged with people.
    戏院散场以后，街上顿时挤满了人。
25. His story was seen through at once.
    他的谣言一下就被识破了。
26. Go at once while there's still time.
    马上去还赶趟儿。
27. It's getting late. Run home at once.
    天晚了，快跑回家去。
28. On hearing that the new novel was published, he rushed at once to the bookshop for a copy.
    听说那本小说出版了，他就迫不及待地跑到书店去买。
29. The meeting hall was seething at once.
    会场上顿时沸腾起来了。
30. She told him to leave the room at once.
    她要他马上离开房间。

  immediately at once instantly right away【导航词义：立刻，马上】

  immediately adv. 即刻，马上

〔辨析〕指毫不耽搁地，也可指某一事件刚一发生，另一事件便紧接着发生，中间几乎没有时间间隔。

  at once adv. 立刻，马上

〔辨析〕词义同 immediately，强调一刻也不耽误，但常用于口语中。

  instantly adv. 立即，马上

〔辨析〕词义同 immediately，但语气更强。

  right away adv. 马上，立即

〔辨析〕词义同 at once，可换用。

adv

1. without delay or hesitation
   1. he answered immediately
   2. found an answer straightaway
   3. an official accused of dishonesty should be suspended forthwith
   4. Come here now!

   Synonym:    immediatelyinstantlystraightawaystraight offdirectlynowright awayforthwithlike a shot

2. simultaneously
   1. he took three cookies at a time

   Synonym:    at a timeat one time