so long a time为什么加a,time不可数吧,为什么还要加a?那有没有such a long time 的说法?

so long a time为什么加a,time不可数吧,为什么还要加a?那有没有such a long time 的说法? 请问为什么有so a long time而没有such a long time? so long 和for a long time 有什么区别 for very long time与 for a very long time区别she has lived abroad for a very long time正确还是不加a 正确?为什么 We have been good friends a long time.这里的a long time之前不用加for吗?为什么? in a huryy,walked a long time 为什么要加a呀 a long time 时间不是不可数吗?为什么可以加a It takes a long time to get there和I have been here for a long time,为什么一个加for一个不加 “一段时间”应该说“a few time”还是“a long time”?为什么? it take me a long time 英语中long time前为何加a? long time ago 前面一定要加 a 也就是一定是 a long time ago we have been best friends for a long time中friends为什么要加s I'm going away for a long time.为什么这里going后面不用加to呢? So short a time为什么用a A long time ago 与 Long time agoLong time ago前必须加a吗?在句子中只用long time ago,不加a,符合语法吗? having been ill for a long time,so she ell behind her classmates为什么so是多余的?急having been ill for a long time,so she ell behind her classmates为什么so是多余的?having been ill for a long time,so she fell behind her classmates为什 long time和a long time区别? A long time 请求,