Not hold one's breath 一是指没有在等待什么事发生;二是指不要寄太大希望.看下面的解释和例句:
An expression used to mean one is not awaiting something
例句:I'm hoping to hear if I got the job,but I'm not holding my breath.
It often is put as an imperative,don't hold your breath,meaning “don't expect it,it's not likely.”
例句:
They may get married this summer,but don't hold your breath.
This expression in effect implies it is unwise to stop breathing until a particular event occurs,since it may never come to pass.