Ключевые слова: atom, biology, boat, city, clean, climate, collection, concept, conservation, country, cyclic, earth, ecology, electricity, element, energy, environment, environmental, factory, flat, fuel, generation, global, green, house, industry, landscape, leaf, nature, nuclear, organic, panoramic, plant, pollution, power, protection, recycling, sea, sign, simplicity, sky, solar, sun, symbol, technology, view, village, water, wind,