Ключевые слова: adult, african, american, background, black, blackboard, board, business, businesswoman, chalk, chalkboard, classroom, college, concept, copyspace, development, education, female, floral, girl, graph, growth, hand, indoors, inside, knowledge, lady, lesson, perfect, personal, school, signal, student, study, studying, subject, teach, teacher, three, woman, write, young,