The extinction of dinosaurs
December 17, 2009 9:41am CST
65 million years ago, dinosaurs disappeared from the face of the earth. These giants reptiles lived in our planet for a long time. Why did they extinguish? Most scientists think it was because of an asteroidthat crashed against the earth, causing deep climate changes that dinosaurs couldn't face up. Some other think it was because they lost its battle for survival against mammals, which were better adapted to the environment. Why did dinosaurs disappear? What do you think? What's your viewpoint?