n.磨刀石；砂輪

Our factory produces grindstone. 我們工廠生產(chǎn)磨刀石。

They ground the knife on a grindstone. 他們?cè)谀サ妒夏サ蹲印?/p>

It's a pity I have to get back to the grindstone. 遺憾的是我不得不回去工作。

The teacher believed in hard work and always keep our nose to the grindstone. 老師提倡勤奮，而且也總是要我們埋頭讀書。

I always admire men, even the dullest, who know their job and put their noses to the grindstone. 我一向敬重那些有專長(zhǎng)且做事勤奮不懈的人，包括那些最沒(méi)情趣的人。