英语六级阅读辅导题及答案

英语六级阅读辅导题及答案TheLookYoungerDietIstheFountainofYouthamyth?Notentirely,manyexpertsinnutritionnowbelieve,"Agefast,orageslowit'suptoyou."declaresDr.KennethCooper,presidentandfounderoftheAerobicsCenterinDallas.JeffreyBlumberg,associatedirectoroftheU.S.DepartmentofAgriculture'sHumanNutritionResearchCenteronAgingatTuftsUniversityinBoston,agrees,"Researchshowsthatmanyso-calledage-relateddeclinesinphysiologicalfunctionseemtohavelesstodowithagingthanwithenvironmentalfactorslikedietandexercise."Obesity(过度肥胖)isoneoftheleadingcausesofacceleratedaging,accordingtoCooper,"Ifyouloseweight,stopsmoking,andexercise,"hesays,"youcanslowtheagingprocessandmakedramaticchangesinyourlooksinarelativelyshortperiodoftime."A37-year-oldsalesdirectorforaBostoncomputer-distributioncompanyisaprimeexample.Oversixfeettall,hehadbeenconsiderablyoverweightmostofhislike.Thenhebegantoworrythathisappearancecouldbehurtinghiscareer."IgottiredofpeoplethinkingIwasthesameageasmybrother,who'snearlynineyearsolder,"hesays,"Whenyou'refat,peopleinthebusinessworldassumeyou'reoutofcontrol."Determinedtochange,thesalesdirectorenteredahospital-baseddietprogramanddroppedover70pounds."Ifeelandlooktenyearsyounger."hesays.At82,ClariceR.McWilliams,aretiredbusinessownerinDallas,hastheappearance,skintone(肤色)andmentalagilityofsomeonemanyyearsyounger."MostpeoplethinkI'minmy60s."sheboasts.McWilliamsadmitsgenesplaysomeroleinthewayshelooks,butbelievesdietisanimportantfactor."Itdoesn'tmatterhowgoodthegenesareifyoudon'teatproperlyandtakecareofyourself,"shesays."Ifyouwanttolookgood,getplentyofrest,exerciseeveryday,eatmostlyrawfruitsandvegetablesandquitworrying."SaysBlumberg,"There'scertainlyalinkbetweengoodnutrition,apositiveattitudeandimprovedqualityoflife.Peoplecanhaveasayinwhat'sgoingonwiththeirbodiesbyselectingahealthfuldiet."Skin.Nowheredothesignsofagingmanifestthemselvesmoreclearlythanintheconditionoftheskin.Whenyourweightfluctuates,theskinstretcheswitheachupcycle,butitmaynotcompletelyshrinkbacktoitsoriginalsizeinthedowncycle.Asaresult,theskinmaysag(松弛下垂).Aseverelydeficientdietcanleadtoskindisorders,dramaticallyaffectingone'sappearance.Bythesametoken,awell-balanceddietwithamplesuppliesofnutrientsisthoughtbymanyexpertstoproduceaglowing,youngerlook.ZincandvitaminAareimportantfornormal,healthyskin.Zinchelpstheskinrepairitself,andvitaminAaidsinkeepingskinsupple,preventingdrynessandhelpingsheddeadcells.Goodsourcesofzincarebeef,eggsandseafood,whilemanydark-greenleafyvegetablesarerichinbetacarotene,whichthebodyconvertstovitaminA.Otherfoodscontainingampleamountsofbetacaroteneincludecarrots,cantaloupe,wintersquash,sweetpotatoes,sweetredpeppers,apricotsandmangoes.VitaminChelpsimprovethebloodsupplytotheskinandaidsinformingcollagen(胶原),thefibrousproteinthatliesbeneaththeskin'ssurfaceandgivesitasmoothappearance.GoodsourcesofvitaminCincludecitrusfruitsandjuices,Brusselssprouts,cauliflower,snowpeas,redandgreenpeppers,broccoli,whiteandsweetpotatoes,tomatoes,watermelon,honeydewmelonandcantaloupe.Greensareexcellentsourcesofskin-preservingnutrientsand,generally,thedarkertheleaves,themorenutritious.Romainelettuce,forexamplehasaboutsixtimesasmuchvitaminCandeighttimesasmuchbetacaroteneasiceberglettuce.Howfoodispreparedmatterstoo.Thelongervegetablescook,thegreaterthelossofvitaminsandtexture.Don'tsoakvegetableswhenwashingthem,sincewater-solublevitaminssuchasCwillbelost.Blumbergalsorecommendsdrinkingsixtoeightglassesofwaterorotherfluidseachdaytohelpkeepskinandothertissueshydrated."That'sespeciallyimportantforolderpeople,"hesays,"whoareatriskfordehydrationbecausetheirthirstdrivebecomesbluntedwithage."Coffee,colasandteaaren'tthebestsources,sincetheycontaincaffeine,adiureticthatinduceswaterloss.Hair.Healthy,shininghairissecondonlytovibrantskinformakingonelookyounger.Yetmanypeopleunwittinglymistreattheirhairbyeatinganunbalanceddiet.Whena33-year-oldemployeeataTexascorporationdecidedtoloseweightquickly,shewentonafaddiet,highinfiberandbulk,butlowinprotein.Overthreemonths,shelostalotofweight.Shealsolostagooddealofherhair.Dermatologist(皮肤病学家)DavidAlkek,aclinicalprofessorattheUniversityofTexasSouthwestMedicalCenteratDallas,seestoomanycaseslikethiswoman's.Whendietsdon'tcontainenoughaminoacids,thebuildingblocksofprotein,there'sdramaticincreaseinhairlossasthebodybreaksdownitsownprotein.Hairandskincellsareconstantlyreproducingandare,therefore,verysensitivetonutritionaldeficiencies,explainsDr.Alkek.Foodshighinaminoacidsincludemeats,eggs,milk,grainsandlegumes.Justrememberthatthebodycannotstoreprotein.Sofoodshighinproteinmustbeingesteddaily.UnderAlkek'scare,thewomanbeganeatingnutritionallybalancedmeals,andherhairwasrestoredinabouteightmonths.Immunesystem.VitaminsEandCandbetacarotene,knownasantioxidants(抗氧化剂),areconsideredpowerfuldisease-fighters,capableofslowingdownorpreventinganumberofailmentstypicallyassociatedwithaging.Agrowingbodyofevidencesuggeststhataginganddeclineinimmunefunctionmayresultinpartfromaccumulateddamagetocellscausedbycertaintoxiccompoundscalledfreeradicals(自由基).Antioxidantsseemtocounteractorimpairtheabilityofthesesubstancestoattackhealthycells,thusavoidingatleastsomeofthedamage.Foodscontainingthesenutrientsarebeinglinkedbyscienceratherthanmythtothecontrolandpreventionofheartdiseaseandcancer,stroke,cataractsandtothebody'sabilitytowardoffinfectiousdiseases.Goodgeneralnutritionisessentialtomaintainingahealthy,youthfulappearance.Andthekeytogoodgeneralnutritionisbalance.Proteinsshouldmakeuproughlytenpercentofyourdailycalorieintake;nomorethan30percentshouldcomefromfats;andtheremainingcaloriesshouldcomemostlyfromcomplexcarbohydrate