tool edge的用法和樣例：
例句
- A single-point tool has only one cutting edge, while a multiple-point tool has two or more cutting edges.
單刃刀具只有一個切削刃，而多刃刀具有兩個或兩個以上的切削刃。 - He sharpened the edge of his knife on a grindstone.
他在磨石上磨快了他的刀刃。 - Pity lack of a section on edge,but it shows its rigid blade.
遺憾的是刀鋒上缺了一小塊，不過可以顯示出刀刃夠硬的。
