Ключевые слова: alphabet, apprenticeship, background, business, chalkboard, close, closeup, concept, distance, education, elearning, exam, help, horizontal, information, keyword, knowledge, learn, learning, lesson, letters, message, metaphor, note, paper, professional, research, school, sign, skill, states, study, success, symbol, teacher, teaching, text, uniform, white, word, work, written,