Those of us who carried pocket knives for sharpening pencils (most of us) might also carve out rings and spirals when we were bored. We had nothing on these guys though.

我们当中一些口袋里装着削笔刀的(大多数)会在无聊时在铅笔上刻圈子和螺纹，但却从来没雕过这些。

youdao

I am not a sharpening stone effect, can make kitchen knives sharp, although its own cut what. — Horace.

我不如起个磨刀石的作用，能使钢刀锋利，虽然它自己切不动什么。——贺拉斯。

youdao

In Thailand, they still sharpen knives against stones, and it's a skill you have to learn: how not to ruin the knife as you're sharpening it.

在泰国，人们仍然用沙石磨刀。怎样在磨刀时不损坏它，是一门需要学习的技能。

youdao

They stand on their feet for long hours in the cold, sharpening fillet knives and slicing up and de-boning the monkfish, cod and halibut that the fishing boats bring in.

NPR: Economists Untangle Truth About Jobs, Immigration

With two-thirds of American adults tipping the scales these days as overweight or obese, the same lawyers and activists who took on Big Tobacco are now sharpening their knives for their next target: Big Food.

FORBES: How Everybody Can Win the War Against Big Food

As concern over Internet advertising and data collection grows, privacy advocates and the Internet advertising industry have been sharpening their legal knives for more than a year.

FORBES