grindstone [ˈgraɪndstoʊn]

例句:

• Take the sickle which is lying on the grindstone.
  把磨刀石上的那把镰刀拿去.
  
• A knife is sharpened on the grindstone; steel is tempered in fire.
  刀在石上磨, 钢在火中炼.
  
• I will take exams in two weeks, so I'm keeping my nose to the grindstone just at the moment.
  我两星期后要考试, 因而眼下正埋头苦读.
  
• They beg for more money instead of putting their nose to the grindstone.
  来自NEWYORKER
• Several recent studies suggest that the best route to an "aha moment" involves stepping away from the grindstone.
  来自WSJ
• Despite having spent years at the grindstone of comedy appreciation, I wasn't funny.
  来自NEWYORKER