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
배의 내용골은 선체의 강도를 높이는 데 중요한 역할을 합니다.baeui naeyonggol-eun seonche-ui gangdo-reul nopineun de jungyohan yeoghal-eul hamnida.The keelson of the ship plays an important role in increasing the strength of the hull.