关于 count down 和 countdown 区别
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count down
[phrasal verb]
1 : to count numbers in a reverse order from higher numbers to lower ones 倒过来数数，动词词组
▪ He counted down from 10 to 1.
2 count down (something) also count (something) down : to pay close attention to the number of (days, miles, etc.) that remain until a particular moment or event is reached 倒数（如：倒数大运会）， 动词词组
▪ He is counting down the days left in the school year. [=he is eagerly looking forward to the end of the school year] ▪ We were counting down the miles as we approached our destination.
countdown /ˈkaʊntˌdaʊn/ noun
plural countdowns
[count] 1 : the act of counting down the number of seconds that remain before something (such as the launch of a rocket) happens — usually singular 倒数，名词
▪ Begin the countdown. ▪ The engineers stopped the countdown because something was wrong with the engine.
2 : the period of time before an important or special event — usually singular — usually + to
前夕，名词
▪ the countdown to summer vacation ▪ the steady countdown to war
countdown怎么读
读音如下：n.倒数读秒，倒计时(如发射宇宙飞船时);大事临近的时期例句：1.The countdown to Christmas starts here. 现在开始圣诞节倒计时。出现频次2.There were three more things to do before countdown. 开始倒计时之前还有3件事要做。3.The countdown has begun for the launch later today of the American space shuttle .美国航天飞机的发射已于今天晚些时候开始进入倒计时。