AsmanyasoneinfiveUSteenagershavesomedegreeofhearingloss,accordingtoresearchers.Theysaytheproblemisgrowing.“Teenagersreallydon’tpayattentiontohowmuchnoisetheyareexposedto(接触),”JosefShargorodskyofBri

　　AsmanyasoneinfiveUSteenagershavesomedegreeofhearingloss,accordingtoresearchers.Theysaytheproblemisgrowing.

　　“Teenagersreallydon’tpayattentiontohowmuchnoisetheyareexposedto(接触),”JosefShargorodskyofBrighamandWomen’sHospitalinBostontoldReuters.“Oftenpeoplewon’tnoticeit,butevenverylittlehearinglossmayinfluencelanguagedevelopment,”saidShargorodsky,oneoftheresearchers.

　　Thestudycomparedsurveysfromtheearly1990sandthemid-2000s.Eachincludedafewthousandteenagers.Inthefirstsurvey,about15percentofteenagershadsomedegreeofhearingloss.Some15yearslater,thatnumberhadrisenbyathird,tonearly20percent.

　　“Thiscertainlyisbignews,”saidAlisonGrimes,aneardoctor.“Hearinglossisverycommoninoldpeople,”Grimessaid,butsheaddedthatitwasworryingtoseeithappenintheyoungeragegroup.

　　Inbabiesandyoungchildren,hearingproblemsareknowntoslowlanguagedevelopment.Thescienceislessclearforteenagers,butitiseasytoimaginehowbeinghardofhearingcouldinfluencelearning,saidGrimes.

　　Thereasonsfortherisearestillunclear.Whenresearchersaskedteenagersaboutnoiseexposure–onthejob,atschoolorfromactivities,forexample–theteenagersdidn’treportanychange.ButShargorodskysaidthatmightnotbetrue.“Weknowfrombeforethatitisdifficulttoaskthisagegroupaboutnoiseexposure–theyunderestimateit.”FewpeoplewouldcallitnoisewhentheylistentomusicontheirMP3player,forexample.“Thereisadifferencebetweenwhatwethinkisloudandwhatisharmfultotheear,”saidGrimes.

　　Althoughit’snotclearthattheMP3playerscauseteenagers’hearingloss,Grimessaiditwasstillagoodideatoturndownthesoundandtakeshortbreaksfromlistening.

　　小题1:Thewriteradvisesteenagers__________.A．toturnthesounddownB．tostopusingMP3playersC．tobeclearabouttheproblemD．toreportthechangeinhearingloss小题2:Theunderlinedsentence“theyunderestimateit”means__________.A．theirloveformusicpreventthemrealizingtheharmB．theirhearinglossishappeningwithoutbeingnoti