as (so) far as, as (so) long as

as（so）far as的意思是“就……而言（所知）”，as (so) far as sth．is concerned是其中一种具体用法，意为“就某事而言”；

as (so) long as意为“只要”，引导条件状语从句。如：
As far as I know, more than 10 million laid-off workers have found their new jobs．就我所知，一千多万下岗工人已经找到了新的工作。
There is nothing that we can’t do so ／ as long as we keep on trying to do it． 只要我们不断地努力去做，就没有什么事干不成。
As far as the tourism of China is concerned, there is a long way to go．就中国的旅游业而言，需要做的工作还很多。