fast和quickly都什么区别,为什么有时可以混用

fast和quickly都什么区别,为什么有时可以混用 fast和quickly有什么区别? quickly soon fast什么区别` fast和quickly怎么区别 fast和quickly在用法上有什么区别? fast,soon,quickly三词有什么区别 fast和quickly有何区别 quickly和fast soon的区别 walk fast和walk quickly 区别 fast,quickly的区别 fast,quickly,soon区别 rapidly,soon,quickly,fast之间有什么区别? fast与quickly的区别 early/fast/quickly/soon区别 quickly的fast的区别 英语中{fast和quickly}{speak和say}有什么区别,具体的用法是怎样?请详细说明, quickly和fast的区别fast也可以作副词的, as quick as形容名词;as quickly as 形容动词对吗?fast和quick有什么区别?