Ключевые слова: alternative, background, biofuel, biomass, boiler, brown, burn, close, closeup, coal, eco, ecological, economy, energy, environment, example, fire, fireplace, flame, fuel, green, heat, heating, household, korea, macro, mass, material, natural, nature, pellet, pellets, piece, pieces, pile, power, raw, recycling, renewable, shot, structure, technology, template, texture, timber, tracery, up, wallpaper, wood, woodchip, wooden,