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
천문학자들은 성좌표를 사용하여 별의 위치를 찾습니다.cheonmunhakjadeul-eun seongjwapyo-reul sayonghayeo byeol-ui wichi-reul chajseubnida.Astronomers use star maps to find the positions of stars.