题目

In most situations, light helps us see. But nowadays humans are using so much that it is in fact a kind of pollution. When it comes to looking at the night sky, too much light makes it d   76      for us to watch some of life’s most wonderful views: stars, p   77      and even galaxies(星系). According to scientific research, about 2, 500 stars can be seen by the human eye without u   78      any special equipment(设备). But because of light pollution, you can only see 200 to 300 stars from today’s countryside, and no more than ten stars from a city. In most1992年成为中国进一步对外开放的标志的是：A.开放经济特区B.开放沿海港口城市C.开放内地D.开发上海浦东