grinding stone的用法和樣例：
例句
- We suggest sharpening on a wet stone because it cleans the pores of the sharpener dissipates frictional heat and facilitates smooth sharpening action.
我們建議使用一塊弄濕了的磨石，因為研磨液體能幫助清潔磨具上的孔，能散去摩擦產生的熱量，還能使磨刀的動作更加順滑。 - The primary use was elevating water for agriculture, but they were also commonly used to turn millstones for grinding rice and wheat.
最開始主要是應用於農業灌溉，後來漸漸的應用於帶動磨石碾米和小麥。
