count down用法都有什么?

count down用法都有什么?

count down:

(发射火箭等时)倒读数

名词count down:

1.counting backward from an arbitrary number to indicate the time remaining before some event (such as launching a space vehicle)

同义词：countdown

动词count down:

1.count backwards; before detonating a bomb,for example

用法的名词就不用说了，动词的话比如

Count down the number of days

Count down to Christmas 2007

都是倒计时的意思