同学你好，该知识点来自沪江网校《英语零基础直达大学六级【8月班】》的课程，想要更系统的学习，欢迎进入课程学习。不仅可以和更多的同学一起学习，而且还有老师、助教随时的学习指导和知识点解答哦。

同学你好~
from which it is made是定语从句，修饰the water
which指代the water，相当于from the water it is made，也就相当于it is made from the water 从这些水制作而来。
ice is as safe as the water 冰和水一样安全
什么样的水呢，就是from which it is made，也就是做这些冰的水

as… as和……一样……
as safe as 和……一样安全

祝同学学习进步~