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
결여론은 사회적 문제를 이해하는 데 중요한 역할을 한다.Gyeollyeoron-eun sahoejeok munjeleul ihaehaneun de jungyohan yeoghal-eul handa.The theory of deficiency plays an important role in understanding social issues.