milkstone

例句：

1. 1. The milkstone is a type of stone used in cheesemaking.
   奶石是一种用于奶酪制作的石头类型。
2. 2.The milkstone was found in the cave where the cows were grazing.
   在牛群吃草的洞穴里发现了奶石。
3. 3. The milkstone was used to make the cheese that was so popular during the Middle Ages.
   奶石被用来制作中世纪非常流行的奶酪。