所谓的 “到刀子下面 to go under the knife” 意思是动手术，接受手术治疗。
- England‘s best footballer won‘t play at the World Cup. He‘s going under the knife and won‘t recover in time for the start of the tournament.
- I had tonsillitis eight times before doctors decided that I needed to go under the knife and have my tonsils removed.
值得注意的是，不要把这个短语同 put to the sword 混淆，后者的意思是杀戮。
- The captured soldiers should have been kept in a military prison but instead they were put to the sword. Hundreds were killed.