A motorized knife sharpener will give you an adequate edge, but true purists like to do this chore by hand.
电动磨刀器会给你足够的优势, 但真正的纯粹主义者喜欢手工完成这项工作。
哈利波特与死亡圣器
" But they've used you as a knife sharpener, " said Ron, winding slightly as they passed a lamp and Neville's injuries were thrown into even greater relief.
Knife sharpening is the process of making a knife or similar tool sharp by grinding against a hard, rough surface, typically stone, or a soft surface with hard particles, such as sandpaper. Additionally, a leather razor strop, or strop, is often used to straighten and polish an edge.