while的三种意思
while用作连词时，有以下三种含义
意为“虽然，尽管”，引导让步状语从句。
引起条件状语,意思是“只要”。
While he loves his students,he is very strict with them..
虽然他爱他的学生,可是他对他们很严格。
We must strike while the iron is hot.
趁热打铁。
While she was listening to the radio,she fell asleep.
她听着收音机睡着了。
While there is life there is hope.
只要生命存在,就有希望。
