英语高手~~ 是关于英语语法的问题~~ 在线跪求中啊！！

What is not given as an example of a website that may make it unnsafe to make a purchase from?
请问，，，这里最后的from,,, 该怎么看那个from,,,

答：这好象是一个阅读理解题：What is not given as an example of sth.(+定语）？
a website +定语。
定语从句：that may make it unnsafe to make a purchase from
从句分析：that--关系代词作主语=the website
may make--谓语
it--宾语=the website
unsafe--宾补
to make a purchase from 不定式作（状语？）
宾语和宾补在逻辑上是主表关系由下句转换而来：
It is unsafe to make a purchase from
=The website is ...
=to make a purchase from the website is unsafe.
楼主见过：The room is comfortable to live in.这样的句子吗？
不过，如果是4选一，则题为：Which is NOT given as .....?
下面的四个例子中有一个不是作为一个这样的例子来给出的。

that may make it unnsafe to make a purchase from是定语从句，that代替website，to make a purchase from the website

FORM 是PURCHASE带的介词