Ключевые слова: building, business, city, collection, construction, design, different, eco, ecology, electricity, energy, environment, environmental, factory, forms, fuel, gas, green, icon, illustration, industrial, line, machinery, mine, nature, oil, outline, pictogram, plant, power, recycle, renewable, representing, set, signs, solar, station, sun, symbols, technology, tower, transportation, turbine, water, wind,