Dinosaurs died out⑤ suddenly about 65 million years ago.Some scientists think it came after an unexpected incident when a huge rock from space hit the earth and put too much dust into the air.Others think the earth got too hot for the dinosaurs to live on any more.Nobody knows for sure⑥ why and how dinosaurs disappeared from the earth in such a short time. We know many other wild plants,animals,insects and birds have died out more recently.According to a UN report,some 844 animals and plants have disappeared in the last 500 years.The dodo is one of them.It lived on the Island of Mauritius and was a very friendly animal.Next time we will listen to a story of the dodo and how it disappeared from the earth.