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
결석학은 암석의 성분과 구조를 연구하는 학문입니다.Gyeolseokhak-eun amseog-ui seongbun-gwa gujo-reul yeongu-haneun hakmun-imnida.Lithology is the study of the composition and structure of rocks.