so difficult as,as difficult as都一样吗?用法上有区别吗?

so difficult as,as difficult as都一样吗?用法上有区别吗? as difficult as difficult as和as easy as ? as long as、so far as、so long as在意义和用法上有什么区别? as same as和the same as在用法和意义上有区别吗? as far as与as long as在意思都是 只要 上有用法有区别吗? so easy as 与as easy as 用法意思一样吗?举例说明, twic as difficult so...as as...as 有什么区别 请问while和just as用法上有区别吗? as to 和 as for 都是“关于”的意思,有什么用法上的区别吗? as...as与so...as的用法与区别