Fill in each numbered blank with one suitable word or phrase.

Light pollution is not (1)_____ serious as water or air pollution. (2)_______ it is the type of pollution that (3) _____ more in cities than in rural areas. In the past, we could sit out at night and (4) _____ at glittering stars in the sky and light from objects in the outer space. Nowadays, cities are covered with lights from buildings, streets, advertising displays, many of which direct the lights up into the sky and into many unwanted places. The real problem is that it is very (5) _______ to apply light to almost everything at night. Millions of tons of oil and coal (6)_______  to produce the power to light the sky. Eye strain, (7)______  of vision and stress are what people may get from light pollution. (8)________  light at night can harm our eyes and also harm the hormones that help us to see things properly.

In the past, we could sit out at night and (4) _____ at glittering stars in the sky and light from objects in the outer space.