Ключевые слова: apple, back, background, black, blackboard, board, book, books, chalk, chalkboard, child, childhood, class, classroom, concept, concepts, copy, desk, educate, education, elementary, equipment, formulas, green, homework, indoors, knowledge, learn, learning, lecture, library, literary, literature, notebook, object, preparation, preschool, school, stationery, student, studying, supplies, table, teacher, teaching, text, textbook, to, university, wisdom,