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
이 물질은 불가입성이 높아서 빛이 통과하지 못한다.i muljireun bulgaipseong-i nopaseo bich-i tonggwahaji mothanda.This material has high impenetrability, so light cannot pass through it.