初三英语阅读理解精选试题二阅读下面短文，从每题所给的四个选项A、B、C、D中选出最佳选项。6April 22 is Earth Day. Everyone on earth should care about and protect the earth! The earth has warmed by about 1 F over the past 100 years, but why and how? Well, scientists are not quite sure. Maybe the earth gets warmer and warmer on its own. But many scientists say that people are doing many things which make the earth warmer. First, greenhouse effect (效应) is a very important reason for the change of the earth. People give out too
