Ключевые слова: abstract, air, backdrop, background, black, brown, chemical, clouds, cloudy, copy, copyspace, danger, dirty, ecology, empty, environment, environmental, exhaust, forest, gas, global, hill, horizon, industrial, industry, landscape, layout, living, mountain, nature, ozone, plain, poison, pollute, pollution, rain, silhouette, simple, sky, skyscape, smog, smoke, space, steam, toxic, trees, vertical, warming, waste, woods,