Ключевые слова: adult, background, black, blackboard, chalk, chalkboard, class, classes, college, culture, dark, education, educator, explain, female, hand, job, knowledge, learn, lesson, lessons, many, melody, music, musical, note, notes, occupation, people, person, profession, school, signs, song, sound, study, subject, task, teach, teacher, teaching, tutor, university, woman, work, write, writing,