be under the knife

• 动手术

be under the knife的用法和样例：

例句

1. The old woman has to be operated on at once.
   必须马上给这位老太太动手术。
2. Better have the operation right now.
   你最好还是现在就动手术。
3. The surgeon operated on her for a tumor.
   医生为她的肿瘤开刀。
4. The doctor advised an immediate operation.
   医生建议马上开刀。