Ключевые слова: bad, ball, black, blood, board, by hand, calligraphy, centers, chalk, chemistry, cholesterol, concept, council, crete, dna, education, fats, formula, formulas, hand, healthy, heart, heart attack, investigation, life, molecular, molecule, point, science, sign, sketches, speculation, strategy, structural, symbol, tall, to write, white, witty comment, written,