Today I went to National museum of Korea. In the museum, there was a lot of remains of our ancestor. They developed time to  time, and they also got socialized. Before they get socialized, it was called prehistoric period. At then, human beings didn't have language, which means they didn't use letter and words to communicate. And more in detail, prehistoric period is devided in to three parts again. Paleothic age, Neolithic period, bronze age and Iron age. The most developed is Iron age, most indeveloped is Paleothic age. Both Paleothic and Neolithic made tools by stones. In bronze age and Iron age, people found metals.

 Even though bronze was found, it wasn't used very much. That was because bronze was bent too easily. So it was only used as decoration for showing off the power of one. But when iron was found, people began to use it. Also, that was when war started and Historic period started.