Ключевые слова: abstract, america, background, ball, blue, business, care, concept, conceptual, continent, country, crystal, day, earth, eco, ecology, energy, environment, environmental, europe, field, geography, glass, global, globe, grass, green, leaf, life, map, natural, nature, north america, organic, peace, planet, plant, protect, recycle, recycling, shine, shiny, soft, space, sphere, symbol, transparent, warming, water, world,