as as在这里引导的是定语从句.当先行词前有such,the same 时,后面从句结构不完整,少主语,宾语或表语时,常用as.这里缺少动词help的宾语,关系词as来充当,所以用as.
such.that.如此.以至于.这里that引导的是结果状语从句,但that在从句中不做成分,故不选.如果是下面句子则要选that：Lucy is such a lovely girl that her friends are willing to help her whenever necessary .