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
산의 삭박 현상은 토양 침식을 초래할 수 있다.san-ui sakbak hyeonsang-eun toyang chimis-eul choraehal su itda.The denudation phenomenon of the mountain can lead to soil erosion.