as it is considered unlucky for anyone living to eat it.这里的as和for分别是什么用法

as表示原因,
In many countries it is considered rude（for people) to spit in public.在许多国家,当众吐痰被认为是不雅行为.
你可以记这个句型：it is considered +形容词+（for sb)(这部分可省略）+ to do sth全句是the food that had been laid out for the dead is thrown into a river or into the sea as it is..........for可以省略，这是一种固定句型吗it is considered +形容词+（for sb)(这部分根据情况，有时可省略）+ to do sth 是个常用的句子结构The food(主语） that had been laid out for the dead is thrown into a river or into the sea （定语从句）as it is considered unlucky for anyone living to eat it（原因状语），这个句子里 for anyone living就不能省略.