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

土方工程的施工内容包括土方开挖、土方运输和土方（）。

堤防工程竣工验收前，项目法人应委托省级以上水行政主管部门认定的水利工程()对工程质量进行一次抽检。工程质量抽检所需费用由项目法人列资。

水利水电工程施工现场的噪声源主要包括（）。

对重大危险源和重大隐患要报（）备案。