Ключевые слова: abstract, atom, biology, blue, chalk, chemical, chemistry, color, complex, computation, design, difficult, drug, education, element, examination, formula, glasses, line, manuscript, material, medical, medicine, molecular, molecular formula, molecule, organic, painting, paper, particle, pattern, pill, reaction, repeated, research, science, scientific, scratch, scribble, seamless, slate, structure, study, symbol, technology, test, texture, white,