five years before 用法和five years ago的区别

问题描述:

five years before 用法和five years ago的区别

before 以过去某时为起点的.之前
ago 以现在为起点的.之前
he told me that he had finished his university five years before.(现在算起,毕业六年了)
he tells me that he has been in the factory five years ago(入厂五年了)
供参考.