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
그는 적록색맹이어서 빨간색과 초록색을 구별할 수 없다.geuneun jeoknoksaekmaeng-ieoseo ppalkansaekgwa choroksaek-eul gubyeolhal su eopda.He has red-green blindness, so he cannot distinguish between red and green.