gravitational-flow irrigation的用法和樣例：
例句
- Gravity irrigation can increase fruit trees' production volume.
利用自流灌溉可提高果樹的產量。 - The technologies, which include treadle pumps and drip irrigation systems, enable farmers to produce vegetable crops for consumption and sale.
這項技術，包括踏板抽水和滴流灌溉系統，使得農戶可以用於蔬菜灌溉，達到自行消費和出售的目的。
