单项选择题
| We usually think of pollution as a
harmful waste substance that threatens the air and water. (1)
some people have become (2) about another kind of
pollution. It can be everywhere, depending on the time of day. (3)
it is not thought of as a (4) . It is
light. The idea of light pollution has (5) with the increase of (6) in cities. In many areas, this light makes it (7) to observe stars and planets in the night sky. In 1922, the International Dark-Sky Association formed. This organization wants to reduce light pollution in the (8) sky. It also (9) the effective use of electric lighting. Light pollution is the (10) of wasted energy. Bright light that shines into the sky is not being used to provide light (11) it is needed on Earth. (12) designed (13) causes a great deal of light pollution. Lights that are brighter than (14) also cause light pollution. Most people in America are (15) to find out that they are not able to see our own galaxy, The Milky Way, with their own eyes. (16) about three-fourths of Americans cannot see the Milky Way because of (17) light. Objects in the night sky are (18) that provide everyone (19) wonder. But light pollution threatens to prevent those wonderful sights (20) being seen. |