时间状语从句是什么

时间状语从句是由含时间的状语从句组成。
（Link Words:after,as,as soon as,before,each time,every time,once,since,the first time,the moment,until,when,while,etc。）
例句：1)We lowered our voice AS SOON AS we entered the library。
2)THE FIRST TIME I saw a woman opening the door foe a man,I was very surprised。