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XX年大学英语六级阅读段落匹配题练习xx年大学英语六级阅读段落匹配题练习 A Theweather reporton theradio orTV___s youthat it is goingto besunny andhot andthat anorange ozonealert has been issued.What isozone Whatdoes anorange alertmean Whyshould yoube concernedabout itIn this article,we willexamine whatozone is,how itis produced,what healthhazards itposes andwhat youcan doto reduceozone pollution. B Ozone isamolecule ofthree oxygenatoms boundtogether O
3.It isunstable andhighly reactive.Ozone isused asa bleach,a deodorizingagent,and asterilization agentfor airand drinkingwater.At lowconcentrations,itistoxic.Ozoneisfound naturallyin smallconcentrations inthe stratosphere,a layerof Earth’s upper atmosphere.In thisupperatmosphere,ozone ismade whenultraviolet lightfrom thesun splitsan oxygenmolecule O2,forming twosingle oxygenatoms.If afreed atomcollides withan oxygenmolecule,it beesozone.Stratospheric ozonehasbeencalled“good...。