grinding stone的用法和样例：
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.
我们建议使用一块弄湿了的磨石，因为研磨液体能帮助清洁磨具上的孔，能散去摩擦产生的热量，还能使磨刀的动作更加顺滑。 - The primary use was elevating water for agriculture, but they were also commonly used to turn millstones for grinding rice and wheat.
最开始主要是应用于农业灌溉，后来渐渐的应用于带动磨石碾米和小麦。
