Ключевые слова: back, background, blackboard, blurred, blurry, board, chair, chalkboard, child, childhood, class, classroom, college, concept, defocused, desk, education, elementary, empty, furniture, green, high, indoors, inside, interior, learn, learning, lecture, lesson, light, little, nobody, room, school, seat, seminar, sitting, student, study, studying, table, teacher, teaching, training, tutor, university, view, wood, wooden, workplace,