Ключевые слова: adenosine, alkaloid, atom, atomic, atoms, background, biology, bond, c8h10n4o2, caffein, caffeine, carbon, chemical, chemistry, coffee, coffeine, composition, compound, design, drawing, education, element, emblem, flat, formula, graphic, icon, illustration, isolated, laboratory, line, medical, medicine, model, molecular, molecule, nitrogen, organic, oxygen, poster, science, scientific, skeletal, sphere, stimulant, structure, symbol, texture, white,