刀能在一块粗石上磨快.Knives can be sharpened by grinding them against a rough stone.“ 我去弄把刀子来,把钢板也磨磨快." I'll get another knife and have the spring ground.他在磨石上磨快了他的刀刃.He sharpened the edge of his knife on a grindstone....

“磨快”的英语可以翻译为：strickle，whet ...