Ключевые слова: back, background, billboard, black, blackboard, blank, board, box, business, chalk, chalkboard, child, class, classroom, close, college, communication, concept, copy, crayon, dark, design, dirty, drawing, educate, education, elementary, empty, exam, frame, green, grey, highschool, lesson, list, menu, montessori, old, piece, school, simple, stick, student, teacher, teaching, text, texture, university, white, wood,