As+形容詞或副詞+aspossibe,意思是"盡可能……的"。例句：We have to run as fast as possible.我們得盡可能快的跑。（fast屬於副詞）
as習慣用法
1. as soon as
意思是"壹......就......",引導壹個時間狀語從句。如：I'll call you as soon as I finish my homework. 我壹完成我的作業,就給妳打電話。
2. as long as
意思是"長達......之久；只要......"。如：She has searched the information about dinosaurs on the Internet as long as three hours. 她在因特網上搜索有關恐龍的信息已經長達三個小時。
3. as much as
意思是"高達......；與......壹樣多"。是用來表達極其多的語氣。如：Some of the stones weigh as much as fifteen tons.有些石頭重達15噸。
as...as用法：
as...as意為"和……壹樣"，表示同級的比較。使用時要註意第壹個as為副詞，第二個as為連詞。其基本結構為：as+adj./adv.+as。