Polar bear Knut is reflected in a window inside his enclosure at the Berlin Zoo, March 17, 2009.[Xinhua/Reuters]
![Polar bear Knut is reflected in a window inside his enclosure at the Berlin Zoo, March 17, 2009.[Xinhua/Reuters]](http://images.china.cn/attachement/jpg/site1007/20090319/000bcdb95f1d0b2bdfdd1c.jpg "Polar bear Knut is reflected in a window inside his enclosure at the Berlin Zoo, March 17, 2009.[Xinhua/Reuters]")