Thefoodweeatseemstohaveprofoundeffectsonourhealth.Althoughsciencehasmadeenormousstepsinmakingfoodmorefittoeat,ithas,atthesametime,mademanyfoodsunfittoeat.Someresearchhasshownthatperhapseightypercentofcancerisrelatedtothedietaswell,especiallycancerthecolon.Differentculturesaremorepronetocontractcertainillnessesbecauseofthefoodthatischaracteristicinthesecultures.Thatfoodrelatedtollnessisnotanewdiscovery.In1945,governmentresearchersrealizedthatitratesandnitrites,commonlyusedtopreservecolorinmeats,andotherfooddditives,causedcancer.Yet,thesecarcinogenicadditivesremaininourfood,nditbecomesmoredifficultallthetimetoknowwhichthingsonthepackginglabelsofprocessedfoodarehelpfulorharmful.Theadditiveswhichweeatarenotallsodirect.Farmersoftengivepenicillintobeefandpoultry,andbecauseofthis,penicillinhasbeenfoundinthemilkoftreatedcows.Sometimessimilardrugsareadministeredtoanimalsnotformedicinalpurposes,butforfinancialreasons.Thefarmersaresimplytryingtofattentheanimalsinordertoobtainahigherpriceonthemarket.AlthoughtheFoodandDrugAdministration(FDA)hastriedrepeatedlytocontroltheseprocedures,thepracticescontinue.
48.Whatisthemaintopicofthepassage?
A.Foodandourhealth
BFoodandadditives
C.Foodandcancer
DFoodandculture
49AllofthefollowingstatementsaretrueEXCEPT_______.
AFortypercentofcanceriscausedbyproblemsrelatedtofood.
BResearchershaveknownaboutthepotentialdangeroffoodadditivesformanyyears
C.Weeatsomeofthefoodadditivesdirectlyandsomeindirectly
DDrugsarealwaysgiventoanimalsformedicinalpurposes
50.Whydofarmersgivedrugstotheiranimals?
A.tospeedupthegrowthofanimals
BTomaketheanimalsfatter
Ctomaketheanimals’meatfittoeat
DTomaketheanimals’meatrichinnutrients
51.Itcanbeinferredfromthepassagethat_________.
Ascientisthavemadeallthefoodfittoeat
Bonlyinrecentyearshavepeoplefoundthatthefoodisrelatedtoone’sillness
Callkindsofcancerarerelatedtothediet
Dsomeadditivesareharmfultoourhealth
52.Theword“this”inthesecondsentenceofparagraph2mostprobablyrefersto__________.
Afarmer
Bpenicillin
Cbeefandpoultry
Dthefactthatfarmersoftengivepenicillintoabeef
下列哪个滤镜可以减少渐变中的色带（）