请教英语问题He died of cancer,as his father had done.请问这句话能不能用whic

请教英语问题
He died of cancer,as his father had done.请问这句话能不能用which？
有人说不可以，但是书上有这么一句：I live a long way from work,as/which you konw.
To shut your eyes to facts,as many of you do,is foolish.请问as能不能换成which?
有人说这句也不可以
请问这3句的区别在哪里？该怎么判断在这些情况中能否互换？
有人说因为第一句和第三句as解释为正如，正像，所以不能换成which，但是第二句as不是也能解释为正如正像吗？