as long as有“只要”的意思
As long as you keep working,you will get what you want.
as far as 的意思比较抽象,可以表示距离上的“远到,直到”也有“据我所知”的意思,翻译起来可根据上下文语境灵活处理.
As far as I can see,it is a perfect plan.
在我看来,这是个完美的计划.