Ключевые слова: banking, bear, black, blackboard, blank, block, board, bull, business, chalk, chalkboard, class, classroom, classwork, color, conceptual, conference, course, courses, dirty, down, drawing, economy, education, effect, finance, financial, frame, free, free hand, graph, grunge, hand, hand drawn, horizontal, indicators, information instruct, instruction, investing investment, learning, learning lecture, lesson, lessons, marketing, markets, message, messages, messy, money, newspaper, nobody, school, seminar, shares, sketch, sketching, stock, strategy, street, structure, studying, symbol, symbols, teach, teacher, teaching, text, texture, textured, train, training, trend, unwritten, values, wall, wood, wooden, write, writing, written,