it's very kind --you .为什么用of

形容人或物的根本属性时就要用of
如it's nice of you
it's tipical of the government to raise the tax on beer

楼上的那个人明明是在网页上搜索的答案，也好意思说是自己思考得来的，-_-!提供他的链接http://iask.sina.com.cn/b/3681686.html?from=related

表示人的特性

固定用法....
怎么解释呢?

习惯用法，无法解释

kind有多种意思——
名词
1. 种类
2.(动、植物等的)类,族
3.特定种类的人
4.性质,本质

形容词：
1. 亲切的;和蔼的
2.富于同情心的,宽容的
3.【口】体贴的;令人感激的
……

kind of是一个固定用语~

of的用法：
1:表示剥夺,除去

一:deprive sb. of his right

denude sb. of his possession (hope)

divest the baby of his clothes

rid him of this fear rob sb. of his wallet

defraud sb. of gold ring

cure sb. of cancer heal sb. of cancer

purify the nation clean the jar of crust

clarify the river of flowing rubbish