什末意思？

at once: [ ət 'wʌns ]

立刻,马上

例句与用法:
1. He stopped playing the piano at once.
他立刻停止了弹钢琴。

2. If you see anything suspicious, inform the police at once.
你要是看到什么可疑的东西就马上通知警察。

3. When I gave him the chance, he grabbed it at once.
我给他这一机会，他立刻抓住不放。

4. It is necessary that he be sent there at once.
有必要马上派他到那里去。

5. We determined to go to the railway station at once.
我们决定立刻去火车站。

6. Since she is seriously ill, we have to send for a doctor at once.
既然她病得厉害, 我们要马上去请医生。

7. We agreed to leave at once.
我们同意立即离开。

8. The man was so genial, so I was drawn to him at once.
这人这么和蔼, 我立刻为他着迷。

英英解释:
副词at once:

1. without delay or hesitation; with no time intervening
同义词：immediately, instantly, straightaway, straight off, directly, now, right away, forthwith, in real time, like a