In a natural disaster, minutes and even seconds of warning can make the         between life and death.

The manager urged older staff ________early retirement and new staff _______ more time for work.

—________the car seat．It’s wet.　　—Thank you for telling me.

With the development of the central and western China，more and more modem cities have ——in what was a wasteland ten years ago 

I_____the problem _____in my mind for a whole week before I did anything about it.