《纯正英语一分钟》第228课：Ozone Layer

      I first heard about the ozone layer about twenty years ago. I was still in school. I thought it was interesting, but I didn’t take it seriously. It was a bit like science fiction, I mean, how could there be a giant hole in the atmosphere? Over the years, more and more scientists spoke about the ozone layer. Global warming became a serious issue. Important people like Al Gore made movies about it. We all know today that the thinning ozone layer is perhaps the most serious crisis we face today. Even though many people have changed their lifestyles, we are still damaging the ozone layer. We need to do something really drastic to stop this. We all need to stop driving cars and stop using coal. That would be a start.