其实这里的 which 不是指人，而是指人的某种“属性”（具体地说，这种属性包括人的品质、性格、地位等），此时只能用 which，不能用 who。又如：

He is a fool, which you are not. 他傻，你不傻。

He is a cadre, which his sister is not. 他是个干部，他的妹妹就不是了。

She looks like a Russian, which you are not. 她看上去像个俄国人，而你不像。

She thought him a rather annoying child, which he was not. 她认为他是一个相当讨厌的孩子，他并非如此。

She was dressed like an actress, which she was not. 她打扮得像个演员，其实她不是。

Diana is an experienced teacher which her boyfriend was not. 戴安娜是一位经验丰富的教师，而她的男朋友则缺乏经验。