It is an unfortunate fact of today's life that most people are growing up unable to see the stars. The prime night sky exists only【C1】______pictures. This is true not only in cities and suburbs, but also in rural areas. We have lost our view of the stars and【C2】______Our nighttime environment as well. Such a loss might be acceptable if light pollution were the inevitable price of progress, 【C3】______it is not. Most sky glow is unnecessary. It comes mainly from lighting sources that do little to increase【C4】______safety, security or utility. They produce only glare, costing Over one billion dollars annually in the U.S. alone. 【C5】______science, the impact has been even more dramatic. Scientists require observations of extremely faint objects that can only be made with advanced devices at sites【C6】______of air pollution and urban sky glow. For example, some images of the objects can offer information about faraway corners of the universe, helping us understand the way in【C7】______our world was actually formed. Therefore, the light from these objects can be lost at the very end of its【C8】______in the glare of our own sky. Reducing light pollution is not difficult. It requires that public officials and citizens be【C9】______of the problem and act to counter it. As individuals, people can help reduce sky glow just by【C10】______lighting only when necessary. The stars above us are a priceless heritage. We must do our best to preserve it.