Ключевые слова: chemical, concept, conservation, drop, earth, electricity, energy, environment, environmental, factory, forest, fuel, gasoline, global, horizontal, illustration, industry, liquid, natural, nature, oil, organic, pollution, protection, refinery, reflection, resource, round, save, searching, shape, shiny, sign, simplicity, single, sphere, spill, stream, supply, symbol, technology, textured, tree, usa, vitality, water, wet, wind, yellow,