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
상업위성은 통신과 기상 관측에 사용됩니다.sangeomwisesangeun tongsin-gwa gisang gwaljeong-e sayongdoemnida.Commercial satellites are used for communication and weather observation.