The answer is c because if you treat the sewage water than you that means that the water will be clean so it prevents diseases
More than 150 years ago, inventors began working on a bright idea that would have a dramatic impact on how we use energy in our homes and offices. This invention changed the way we design buildings, increased the length of the average workday and jumpstarted new businesses. It also led to new energy breakthroughs -- from power plants and electric transmission lines to home appliances and electric motors.
Like all great inventions, the light bulb can’t be credited to one inventor. It was a series of small improvements on the ideas of previous inventors that have led to the light bulbs we use in our homes today.
It should be equal
nothing is lost, nothing is created