为什么要用a friend of mine而a leg of desk,不用a friend of me

a friend of mine 那为什么 the leg of the chair用chair而不用chair's a friend of mine comes from... 为什么用mine 不用me a friend of mine. a friend of mine 为什么是a friend of mine 而不是a friend of me 呢 of的用法.为什么a friend of mine要用物主代词,而a painting of Tom却不用名词所有格 a good friend of mine 为什么用mine his a friend of mine 为什么用mine 关于a friend of mine a friend of mine= my friend A friend of mine,A friend of myself.哪个对? a friend of my还是a friend of mine