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
저산소 상태는 생명체에 매우 위험할 수 있습니다.jeosanso sangtaeneun saengmyeongche-e maeu wiheomhal su issseubnida.Hypoxic conditions can be very dangerous for living organisms.