protective gap的用法和樣例：
例句
- The installation of an air gap and drain line are recommended.
建議安裝氣隙和排放管道。 - This would create an air gap to eliminate any possible backflow.
這將產生一個氣隙以消除任何可能的迴流。 - The installation of an air gap and drain line are recommended.
建議安裝氣隙和排放管道。 - This would create an air gap to eliminate any possible backflow.
這將產生一個氣隙以消除任何可能的迴流。
