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 분별지는 다양한 색상을 구분하는 데 사용됩니다.i bunbyeoljineun dayanghan saeksangeul gubunhaneun de sayongdoemnida.This discriminating paper is used to distinguish various colors.