ImagineamassoffloatingwasteistwotimesthesizeofthestateofTexas.Texashasalandareaofmorethan678000squarekilometers.Soitmightbedifficulttoimagineanythingtwiceasbig.Alltogether,thismassofwasteflowingintheNorthPacificOceanisknownastheGreatPacificOceanGarbagePatch.Itweighsabout3500000tons.Thewasteincludesbags,bottlesandcontainers—plasticproductsofallkinds.TheeasternpartoftheGreatPacificOceanGarbagePatchisaboutl600kilometerswestofCalifornia.ThewesternpartiswestoftheHawaiianIslandsandeastofJapan.Theareahasbeendescribedasakindofoceanicdesert,withlightwindsandslowmovingwatercurrents.Thewatermovessoslowthatgarbagefromallovertheworldcollectsthere.Inrecentyears,therehavebeengrowingconcernsaboutthefloatinggarbageanditseffectonseacreaturesandhumanhealth.Scientistssaythousandsofanimalsgettrappedinthefloatingwaste,resultingindeathorinjury.Evenmorediefromalackoffoodorwaterafterswallowingpiecesofplastic.Thetrashcanalsomakeanimalsfeelfull,lesseningtheirdesiretoeatordrink.Thefloatinggarbagealsocanhaveharmfuleffectsonpeople.Thereisanincreasedthreatofinfectionofdiseasefrompollutedwaste,andfromeatingfishthatswallowedwaste.Diverscanalsogettrappedintheplastic.Itsexistencefirstgainedpublicattentioninl997.ThatwaswhenracingboatcaptainandoceanographerCharlesMooreandhiscrewsailedintothegarbagewhilereturningfromaracingevent.Fiveyearsearlier,anotheroceanographerlearnedofthetrashafterashipmentofrubberduckiesgotlostatsea.ManyofthosetoysarenowpartoftheGreatPacificOceanGarbagePatch.InAugust,2009,ateamfromtheUniversityofCalifornia,SanDiegobecamethelatestgrouptotraveltoit.Theywereshockedbytheamountofwastetheysaw.Theygatheredhundredsofseacreaturesandwatersamplestomeasurethegarbagepatch’seffectonoceanenvironment.小题1:Howdidthewriterintroducethetopicofthepassage?