It is said that a huge meteorite whose diameter is from 10km to 15km struck the earth sixty-five million years ago. The meteorite impact swirled up dirt and dust until the sky was almost covered. It caused cooling of the earth and all dinosaurs died out because of it. If the meteorite impact had not happened, dinosaurs would have survived and human beings would not have emerged. In that case, dinosaurs may have developed like humans and they could have had their own civilization. Anyway, we are
