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
건축 현장에서 동바리를 사용하여 구조를 지탱합니다.geonchuk hyeonsangeseo dongbarireul sayonghayeo gujo-reul jitanghamnida.In construction sites, puncheons are used to support the structure.