a fast-acting tranquillizing drug的用法和样例：
- He's not a fast horse but he's certainly a stayer.
- Bill has a feeling he is on a fast track.
- That new Fiat is a fast little number.
- Bill had a feeling he was on a fast track.
- He kept a fast hold on the rope.
- The pitcher let go a fast ball and the batter swung and missed.