题目内容：
Questionsarebasedonthefollowingpassage:
Increasingly,overthepasttenyears,people--especiallyyoungpeople--havebecomeawareoftheneedtochangetheireatinghabits,becausemuchofthefoodtheyeat,particularlyprocessedfood,isnotgoodforthehealth．Consequently,therehasbeenagrowinginterestinnaturalfoods．Foodswhichdonotcontainchemicaladditives(添加剂)andwhichhavenotbeenafectedbychemicalfertilizers,widely
usedinfarmingtoday．
Naturalfoods,forexample,arevegetables,fruitandgrainwhichhavebeengrowninsoilthatisrichinorganic(有机的)matter．Insimpleterms,thismeansthatthesoilhasbeennourishedbyunusedvegetablematter,whichprovidesitwithessentialvitaminsandminerals．Thisinitselfisanaturalprocesscomparedwiththeuseofchemicalsandfertilizers,themainpurposeofwhichistoincreasetheamount--butnotthequality--offoodsgrownincommercialfarmingareas．
Naturalfoodsalsoincludeanimalswhichhavebeenallowedtofeedandmovefreelyinhealthypastures(牧场)．Comparethiswithwhathappensinthemassproductionofpoultry:therearefarms,forexample,wherethousandsofchickenslivecrowdedtogetherinonebuildingandarefedonfoodwhichislittlebetterthanrubbish．Chickenskeptinthiswayarenotonlytastelessasfood,theyalsolayeggswhichlackimportantvitamins．
Thereareotheraspectsofhealthyeatingwhicharenowreceivingincreasingattentionfromexpertsondiet．Take,forexample,thequestionofsugar．Thisisactuallyanon-essentialfood!Althoughanaturalalternative,suchashoney,canbeusedtosweetenfoodifitisnecessary,wecaninfactdowithoutit．Itisnotthatsugarisharmfulinitself．Butitdoesseemtobeaddictive:thequantityweusehasgrownsteadilyoverthelasttwocenturiesandinBritaintodayeachpersonconsumesanaverageof200poundsayear!Yetallitdoesistoprovideuswithenergy,intheformofcalories．Therearenovitaminsinit,nomineralsandnofiber．
Itissignificantthatnowadaysfiberisconsideredtobeanimportantpartofahealthydiet．Inwhitebread,forexample,thefiberhasbeenremoved．Butitispresentinunrefinedflourandofcourseinvegetables．Itisinterestingtonotethatincountrieswherethenationaldietcontainslargequantitiesofunrefinedflourandvegetables,certaindiseasesarecomparativelyrare．Hencetheemphasisisplacedontheeatingofwholemealbreadandmorevegetablesbymodernexpertson"healthyeating"．
Peoplehavebecomemoreinterestedinnaturalfoodsbecause（ ）． A．theyaremorehealthconscious
B．theywanttotasteallkindsoffoods
C．naturalfoodsaremoredeliciousthanprocessedfoods
D．theywanttoreturntonature
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