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
병인학의 연구는 질병의 원인을 이해하는 데 중요하다.byeonginhag-ui yeonguneun jilbyeong-ui wonin-eul ihaehaneun de jungyohada.Etiological research is important for understanding the causes of diseases.