磨杵

例句：

1. 1. He used a wooden block to sharpen his knife on the stone.
   他用一块木头块来磨他的刀。
2. 2. The old man spent hours grinding his tools on the stone bench.
   老人花了很多小时在石头工作台上磨他的工具。
3. 3.The chef was using a stone grinder to prepare the ingredients for the dish.
   厨师正在用石头研磨器准备这道菜的原料。