a fast-flowing stream的用法和样例：
- A flowing stream inarms a boulder in its passing.
- He's not a fast horse but he's certainly a stayer.
- Bill has a feeling he is on a fast track.
- This filter is designed to have very little back pressure and is easy to squeeze with a faster flow rate.
- That new Fiat is a fast little number.
- Bill had a feeling he was on a fast track.