Ключевые слова: african, american, asian, blackboard, board, book, boy, caucasian, chalk, chalkboard, cheerful, class, classroom, creativity, desk, diverse, education, explaining, formula, fruit, hand, idea, imagination, knowledge, learn, learning, lesson, lifestyle, math, positive, professor, reading, school, science, shape, solution, standing, strategy, student, study, studying, teacher, teaching, teenage, volunteer, volunteers, working, write, writing,