词汇:
astronomer n. 天文学家 migrate v．迁移，迁徒
Illuminate v. 照明，照亮disruptive adj．扰乱性的
haze n．薄雾 obscure v．使变模糊
faint adj．微弱的，暗淡的
注释：
1. University Corporation for Atmospheric Research (UCAR) : 大学大气研究社团，于1960年在美国科罗拉多州(Colorad0，缩写为Col0．)的玻尔(Boulder)市成立。该社团是一个由国内外大学组成的非营利性协会，致力于大气周围的空气和气候变化研究。
2. stargazing : 该词是个合成词，由star和gaze+in9组成，在此意为：观望星星。
3 making them go off course: 使它们偏离飞行路线。course：路线。
练习：
31、When can people see 14,000 stars?
A:When they have a fairly good telescope.
B:When they are in a large city.
C:When the night sky is clear of clouds, moonlight and artificial lights.
D:When the night sky is without haze and fog.
本题正确答案为:C
本题解析: 第一段的第一句提供了答案。在没有云，没有月光，没有人造光源的情况下，可以看见14，000颗星星。
32、Which of the following statements is NOT related to light pollution?
A:A haze of light is formed from artificial lights such as streetlights and building lights.
B:Lights from different sources in the city stream into space and illuminate the night sky.
C:The night sky is illuminated by the lights from big glowing cities in the night.
D:Stargazing becomes difficult because there is a layer of haze in the air.
本题正确答案为:D
本题解析:A、B、C所述内容均可在第二段中找到。D所表达的意思不符合原文，因为a layer of haze in the air的意思是“空气中有一层薄雾”。
