Q: Does a bone marrow transplant change your DNA?

http://www.ted.com Empathy, cooperation, fairness and reciprocity -- caring about the well-being of others seems like a very human trait. But Frans de Waal shares some surprising videos of behavioral tests, on primates and other mammals, that show how many…

家猫看不出来群居会给他们自己带来任何好处，所以它们离群索居，而且猫也不听人的指挥，这一点你问养猫的人就知道了。