一道英语阅读问题

Scientistsestimatethatmorethan60percentofcancerdeathsintheUnitedStatesarepreventablethroughlifestylechanges.Althoughthereisnocertainwaytoavoidallcancers,reducingindividualriskfactorssignificantlydecreasesthelikelihoodofgettingmanyformsofthisdangerousdisease.

TheAmericanChemicalSocietyestimatesthatsmokingcausesnearly30percentofallcancerdeathsintheUnitedStates—thatis,about166,000cancerdeathseachyear.Allcancerdeathscausedbytobaccosmokingcouldbepreventedcompletelybynotsmokingandnotusingsmokelesstobacco.Forthosewhoalreadysmoke,quittingwillreducetheriskofdevelopingcancer.Studiesshowthatafterabouttenyearsofnotsmoking,apastsmoker’srisklowerstoaboutthelevelofthosewhohaveneversmoked.

Afterquittingsmoking,eatingahealthydietisthebestwaytolowertheriskofcancer.Certainfoodshavebeenfoundtoprotectagainstcancer.Amongthesefoodsarecabbage,tomatoes,soyproducts,andfoodshighinvitaminsA,C,andE.Inaddition,greenandpossiblyblackteascontaincompoundsthatprotectthebodyfromcancer-causingsubstance.

Tolowercancerrisk,dietsshouldincludelittleornoredmeat.Otherfoodstoavoidorconsumeinmoderationincludesugar,fatfromanimalproducts,andsalt.Addedfatsandoilsshouldcomefromvegetables,suchasolivesorcorn,ratherthanfromanimalsources.Carbohydrates(碳水化合物)shouldcomefromwholegrains,suchasbrownriceandwholewheatbread,ratherthanfromprocessedfoods,suchaswhitericeandwhitebread.

Theriskofcanceroftheesophagus(食道)increaseswithheavyalcoholconsumption,andmanystudiessuggestthatconsumingalcoholicdrinksincreasestheriskofbreastcanceraswell.Studiesshowthatlimitingintaketotwodrinksadayformen,andonedrinkperdayforwomen,reducescancerrisk.

Lowlevelsofphysicalactivityhavebeenimplicated(牵连)insomecancer.Moderateactivityfor30minutesadayenhancestheimmunesystem,shortensthetimefoodtakestomovethroughtheintestines(肠),andchangesbodycompositionandhormonelevels.Researchersarestudyinghowtheseeffectsmightlowercancerrisk.

78.Whatkindofpeopleincreasetheirchancesofgettingcancer