Ключевые слова: background, bills, bulb, calculation, calculator, changing, class, creative, dollar, eco, ecology, economical, efficiency, efficient, electric, electrical, electrician, electricity, energy, energysaving, environment, equipment, glass, housekeeping, lamp, lay, led, light, lightbulb, modernization, new, old, purse, recyclable, recycling, replace, saving, space, wallet, yellow,