应该是quiet,'安静的'
as引导让步状语从句时,状语表语及谓语动词的一部分置于as之前,且表语
中的冠词要省略.如：Try as we did we failed again.又如：Late as he
came he saw the famous man.而although则无此种用法,句中although应改为 as.
as引导让步状语从句时,常放在作表语,状语或谓语的一部分的形容词,名词,副词或动词原形之后.如果是单数名词或形容词的最高级作表语,不再用冠词.
however和as 引导让步状语从句时的区别：
however引导让步状语从句时,相当于no matter how,后面跟形容词或副词；as引导让步状语从句时,用倒装语序,即把作状语的副词或作表语的形容词或名词提前,而且如果作表语的是单数名词,前面不加冠词,也可以把谓语动词部分的实义动词提前.
〔误〕 As hard he works, he can’t catch up with his classmates.
〔正〕 However hard he works, he can’t catch up with his classmates.
〔析〕见上述说明.
〔误〕 A model worker he is, he remains modest.
〔正〕 Model worker as he is, he remains modest.
〔析〕as 引导让步状语从句,前面的单数名词前不加冠词.
http://sq.k12.com.cn/bbs/index.php?t=tree&rid=0&th=211312&mid=1177919
我在网上找到的这个：
http://ks.cn.yahoo.com/question/?qid=1406082912628