burr mill

例句：

1. 1.The burr mill was a crucial part of the ancient agricultural machinery.
   磨坊是古代农业机械中至关重要的部分。
2. 2. The farmer used to grind his grains in a burr mill every morning.
   这位农民以前每天早上都会用磨坊来磨他的谷物。
3. 3.The old millstone still stands as a testament to the skill and dedication of its builders.
   古老的磨石仍然矗立着，见证了建造者的技巧和奉献精神。