What type of person would send such a note? Was it an enemy? Of course! But what kind? An acquaintance? A stranger? Or how about a neighbor that lives a few feet away?

什么样的人会寄这样一张字条？是敌人？当然了！但是是什么样的敌人？萍水相逢？还是陌生人？或者就是一个街坊邻居？