before you can say Jack knife

• 马上；立即

before you can say Jack knife的用法和样例：

例句

1. You look not well,you'd better go to see a doctor.
   你脸色不太好，最好马上去看一下医生。
2. They cannot readily agree to it.
   他们不能对此马上作出应诺。
3. I desire you to set to work at once.
   我希望你立即开始工作。
4. Please wire as soon as you hear.
   你一听到就请立即拍电报给我。