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
사대성의 국가들은 국제 정치에서 큰 영향을 미친다.sadaeseong-ui gukgadeul-eun gukje jeongchi-eseo keun yeonghyang-eul michinda.The countries of the Four Great Powers have a significant influence in international politics.