Youmayhaveheardadultssaytheyareuncomfortableinthemorningwithoutacupofcoffee.Onereasontheymayfeelthatwayisthatcoffeecontainscaffeine(咖啡因).Caffeineoccursnaturallyincoffeeteaandcocoabeanswhichareusedt

　　Youmayhaveheardadultssaytheyareuncomfortableinthemorningwithoutacupofcoffee.Onereasontheymayfeelthatwayisthatcoffeecontainscaffeine(咖啡因).Caffeineoccursnaturallyincoffeeteaandcocoabeanswhichareusedtomakechocolate.Butnowfoodmakersareaddingittomanyproductsfrompotatochipstowater.

　　TheUSgovernmentisespeciallyworriedabouttheproblem.That’swhytheFoodandDrugAdministration(FDA)isstudyingthehealtheffectsofcaffeineonyoungpeople.Studiesshowthattoomuchcaffeinecanmakepeoplenervousandunabletosleep.What’smorecaffeineishabit-forming.Thosewhoconsumeitregularlyandstopsuddenlymayexperienceheadachesandfeeltired.

　　Oneofthebiggestconcernsisthelargeamountofcaffeineaddedtoso-calledenergydrinkslikeRedBull.A12-ouncecanofcolahasabout35milligramsofcaffeine.AsimilarservingofRedBullcontainsmorethanthreetimesthatamount.

　　TheInstituteofMedicineisalsoworkingoncaffeine-safetymeasures.“Teenagersshouldnotdrinkbeveragesthatcontaincaffeine.Theyshouldbeawareofcaffeine’seffectsonhealthandonhowthebrainworks.Takeforexampleteenagerswhoconsumecaffeinetostayawakeandstudyforatest.Theywillrememberlessofwhattheyjuststudied”saidStallingsamemberoftheinstitute.

　　Companiesthatmakeproductswithaddedcaffeineclaimtheydonotadvertisethemtokids.Howeverthereisnolawtostopchildrenfrombuyingthem.SotheFDAneedstosetlimitsoncaffeineespeciallyinenergydrinks.Asforaddedcaffeineinfoodsthegovernmentshouldjustsayno.Ifnottheamountofcaffeineshouldbeprintedonfoodlabelstoremindconsumers.Thegovernmentmustdothat.

　　Doctorssaykidsshouldavoidcaffeine.Ifyouneedextraenergytrythesenaturalboosters:eatrightexerciseandgetplentyofsleep.

　　32.WhatistheUSgovernmentparticularlyconcernedabout?

　　A.Thefactthatcoffeecontainscaffeine. B.Themeasuresofavoidingcaffeine’seffects.

　　C.Thepracticeofaddingcaffeinetofoods. D.Thepracticeofusingcaffeinetomakechocolate.

　　33.RedBullislistedinthethirdparagraphasanexampleof_____.

　　A.drinkswhichcontainmuchcaffeine