Black Friday: lifetime access is on a special offer in the app, until November 30. Black Friday: special offer on lifetime access, until November 30. Download
조선시대에는 공납제가 중요한 역할을 했다.Joseonsidaeeneun gongnapje-ga jungyohan yeogaleul haetda.During the Joseon Dynasty, the tribute system played an important role.