Weallknowthatcleanairisimportanttogoodhealth.Whereveryougoandwhateveryoudo,youarealwayssurroundedbyaseaofgasesthatwecallair.Ifthereareimpuritiesintheair,theymaybeabsorbedbyourbodiesandmakeusill.Weneedcleanair,butunfortunately,airpollutionisgloballypresent,especiallyincities.
Manylargecitiesareanythingbutpollution-free.Ourcitieshavemanyfactories,whichweneedtomakefood,clothingandotherthings.Everyyearthesefactoriespourmillionsuponmillionsoftonsofsmogintoair.Powerplantsandhousesthatburncoaladdgreatlytoairpollution.Besides,therearemorecarsincitiesnow.Onceoutonthestreets,theywilltakeinfreshairandreplaceitwithpoisonousgases.
Ourcountryistryinghardtopreventandcontrolairpollution.Aslongaseverycitizenalsorealizesitsimportanceandmakesjoinefforts,thedaywillcomesoonwhenpeoplewilltakeinonlycleanair.Then,thesunlightwillnolongerbeblackenedoutbysmokeandsoot.