grind for的用法和樣例：
例句
- Find level ground for the picnic table.
找一處平坦的地面放野餐的餐桌。 - Early experiments with military rockets prepared the ground for space travel.
早年對軍用火箭進行的實驗為發展航天技術奠定了基礎。 - Does desertion ground for divorce?
被配偶遺棄是離婚的理由嗎？ - This citadel is built on high ground for protecting the city.
這座城堡建於高處是為保護城市。
