Today, i went to Amsadong prehistoric site. Isaw stone age, Bronze age and Iron age. In the stone age,  There were old stone age and new stone age. In old stone age, you crash the rock an use pieces f them. But in the new stone age, you grind a stone and make sharp and flat tools. 

In bronze age, People learned to make bronze. They used bronze to symbolize the strength of the leader. It was important.

In iron age, People learned to make iron. Iron was used to fight, farm and hunt. In the invasion or war, iron was very important. Because it was better than stone or bronze.

Thank you for lisening my presentation.