on-the-spot

例句：

1. 1. The policeman was called to the scene of the accident immediately.
   警察被叫到事故现场。
2. 2. He needed to be at the spot to witness the event.
   他需要在现场见证这一事件。
3. 3. The firefighters were on the spot to put out the flames.
   消防员立即赶到现场扑灭火焰。