粗石

Knives can be sharpened by grinding them against a rough stone.

刀能一块粗上磨快。

"The simplest stonework is rubBle, roughly Broken stones Bound in mortar. Ashlar work consists of regularly cut Blocks with squared edges."

最简单的料加工品粗,磨机中粗略地破碎的头。方加工品由整齐地切割出具方形边缘之块所。