Today, I went to mueum of natural history. Firstly, I learned about Big -Bang. When this happened, our solar system was formed. When the earth was made, there was one big continent. But after many volcanoes erupted and earth quakes happened, the continent was divided into several parts. Now, I will explain to you about the living thing on the earth. In Precambrian Era, there were several Cyanobacteria that lived on the earth. This produced oxygen, so that living things can live. In Paleozoic, Mesozoic, Cenozoic Era, there were many living things including dinosaur in the earth. We can divide the dinosaur into two parts. There is Carnivores and Herbivores. Carnivores ate meat and Herbivores ate plant. So Carnivore had more sharper teeth than Herbivore. Also, Herbivores had weapons and armor that protected themselves. So sometimes, Carnivor had hard catching the Herbivorous. But at last all of the dinosaurs extincted. There is alot of theories in it. The theory that I believe the most is the volcano theory. This is the theory that talks about, when huge volanoes erupt, the large smoke covers the sky, so alot of plants die because there is no sun. So Herbivores dies and when Herbivores die carnivore can't eat and die too. However, I learned alot of things in the museum of natural history.