Ключевые слова: air, allergy, alpine, alps, asthma, building, chimney, chimneys, christmas, clouds, cold, ecology, emissions, energy, environment, europe, exterior, fireplace, fog, frozen, furnace, heating, holiday, home, house, landscape, mountain, mountains, nature, outdoor, peaks, pollution, rock, rocks, roof, season, silhouette, ski resort, sky, smoke, smokestack, smoking, snow, stack, swiss, switzerland, tourism, travel, vacation, warming, winter,