Ключевые слова: arm, blackboard, board, chalk, chalkboard, class, classroom, close, college, copy, desk, dirty, drawing, education, elementary, empty, female, green, hand, handwriting, holding, human, knowledge, learn, learning, lesson, object, people, person, primary, school, space, student, symbol, teach, teacher, teaching, text, texture, university, up, wall, white, work, write,