Thechartbelowgivesinformationaboutglobalsalesofgamessoftware,CDsandDVDorvideo.Writeareportforauniversitylecturerdescribingtheinformation.Youshouldwriteatleast150words.Youshouldspendabout20minutesonthistask.modelanswer:Thechartshowsthechangesinthesalesofvideomaterial/DVDs,gamessoftwareandCDsaroundtheworldinbillionsofdollarsoverathree-yearperiod.Itcanbeseenthatthesalesofvideos/DVDsandgamessoftwarehaveincreased,whilethesalesofCDshavegonedownslightly.Between2000and2003,thesaleofvideosandDVDsrosebyapproximately13billiondollars.In2000,justunder20billiondollarsworthoftheseitemsweresold,butin2003,thisfigurehadrisentoalittleover30billiondollars.Thesalesofgamessoftwarealsoroseduringthisperiod,butlesssharply.Salesincreasedfromabout13billiondollarsin2000tojustunder20billiondollarsthreeyearslater.Bycontrast,duringthesametimeperiod,thesaleofCDsfellfrom35billiondollarsin2000toabout32.5billiondollarsin2003.Eatingsweetfoodsproducesacidinthemouth,whichcancausetoothdecay.(HighacidlevelsaremeasuredbylowpHvalues)Describetheinformationbelowanddiscusstheimplicationsfordentalhealth.Youshouldwriteatleast150words.Allowyourself20minutesforthistask.modelanswer:Anyonewhohasvisitedadentisthasbeentoldthateatingexcessiveamountsofsweetsrisksharmingtheteeth.ThisisbecausesweetslowerpHlevelsinthemouthtodangerouslevels.WhenthepHlevelinthemouthiskeptabove5.5,acidityissuchthatteethareunlikelytobeindangerofdecay.Sweetfoods,however,causepHinthemouthtodropforatime,andthelongerpHlevelsremainbelow5.5,thegreatertheopportunityfordecaytooccur.Bycomparingfruitsugar,canesugarandhoney,whichareallcommoningredientsofsweetfoods,wefindthatcanesugarlowerspHlevelsforthelongestperiod,thusproducingthegreatestriskofthethree.Approximatelyfiveminutesaftfterconsumingcanesugar,pHlevelsdroptoaslittleaspH3.5.Theythenbegintoriseslowly,butdonotriseabovepH5.5untilatleast30minuteshaveelapsed.Bycontrast,fruitsugar,whichcausesthemouth'saciditytofalltojustabovepH4,posesadangerforashorterperiod:toothdecayisunlikely20minutesafterconsum...
