in which 用法

in which 用法
遇到两个句子 
We live a society in which the medicinal and social use of substances is pervasive.
Humans hace the abilitu to modify the environment in which they live.

这两个句子中in which是不是可以这样改
We live in a society which the ……
……the environment which they live in.
感觉which还可以用that代替的样子,