英语四级试题卷.docx
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英语四级试题卷.docx
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英语四级试题卷
GeneticallyModifiedFoods--FeedtheWorld?
Ifyouwanttosparkaheateddebateatadinnerparty,bringupthetopicaboutgeneticallymodifiedfoods.Formanypeople,theconceptofgeneticallyaltered,high-techcropproductionraisesallkindsofenvironmental,health,safetyandethicalquestions.Particularlyincountrieswithlongagrariantraditions--andvocalgreenlobbies--theideaseemsagainstnature.
Infact,geneticallymodifiedfoodsarealreadyyewmuchapartofourlives.AthirdofthecornandmorethanhalfthesoybeansandcottongrownintheUSlastyearweretheproductofbiotechnology,accordingtotheDepartmentofAgriculture.Morethan65millionacresofgeneticallymodifiedcropswillbeplantedintheUSthisyear.Thegeneticisoutofthebottle.
Yetthereareclearlysomeveryrealissuesthat,needtoberesolved,lakeanynewproductenteringthefoodchain,geneticallymodifiedfoodsmustbesubjectedtorigoroustesting.Inwealthycount,des,thedebateaboutbiotechistemperedbythefactthatwehavearicharrayoffoodstochoosefrom--andasupplythatfarexceedsourneeds.Indevelopingcountriesdesperatetofeedfast-growingandunderfedpopulations;theissueissimplerandmuchmoreurgent:
Dothebenefitsofbiotechoutweightherisks?
Thestatisticsonpopulationgrowthandhungeraredisturbing.Lastyeartheworld'spopulationreached6billion.Andby2050,theUNestimates,itwillbeprobablynear9billion.Almostallthatgrowthwilloccurindevelopingcountries.Atthesametime,theworld'savailablecultivablelandperpersonisdeclining.Arablelandhasdeclinedsteadilysince1960andwilldecreasebyhalfoverthenext50years,accordingtotheInternationalServicefortheAcquisitionofAgri-BiotechApplications(ISAAA).
Howcanbiotechhelp?
Biotechnologistshavedevelopedgeneticallymodifiedricethatisfortifiedwithbeta-carotene(β-胡萝卜素)—whichthebodyconvertsintovitaminA--andadditionaliron,midtheyareworkingonotherkindsofnutritionallyimprovedcrops.Biotechcanalsoimprovefarmingproductivityinplaceswherefoodshortagesarecausedbycropdamageattributiontopests,drought,poorsoilandcropviruses,bacteriaorfungi(真菌).
Damagecausedbypestsisincredible.TheEuropeancornborer,forexample,destroys40milliontonsoftheworld'scorncropsannual]y,about7%ofthetotal.Incorporatingpest-resistantgenesintoseedscanhelprestorethebalance.Intrialsofpest-resistantcottoninAfrica,yieldshaveincreasedsignificantly.Sofar,fearsthatgeneticallymodified,pest-resistantcropsmightkillgoodinsectsaswellasbadappearunfounded.
Virusesoftencausemassivefailureinstaplecropsindevelopingcountries.Twoyearsago,Africalostmorethanhalfitscassava(树薯)crop---akeysourceofcalories--tothemosaicvirus.Geneticallymodified,virus-resistantcropscanreducethatdamage,ascandrought-tolerantseedsinregionswherewatershortageslimittheamountoflandundercultivation.Biotechcanalsohelpsolvetheproblemofsoilthatcontainsexcessaluminum,whichcandamagerootsandcausemanystaple-cropfailures.Agenethathelpsneutralizealuminumtoxicity(毒性)inricehasbeenidentified.
Manyscientistsbelievebiotechcouldraiseoverallcropproductivityindevelopingcountriesasmuchas25%andhelppreventthelossofthosecropsaftertheyareharvested.
Yetforallthatpromise,biotechisfarfrombeingthewholeanswer.Indevelopingcountries,lostcropsareonlyonecauseofhunger.Povertyplaysthelargestrole.TodaymorethanIbillionpeoplearoundtheglobeliveonlessthanIdollaraday.Makinggeneticallymodifiedcropsavailablewillnotreducehungeriffarmerscannotaffordtogrowthemorifthelocalpopulationcannotaffordtobuythefoodthosefarmersproduce.
Biotechhasitsown"distribution"problems.Private-sectorbiotechcompaniesintherichcountriescarryoutmuchoftheleading-edgeresearchongeneticallymodifiedcrops.Theirproductsareoftentoocostlyforpoorfarmersinthedevelopingworld,andmanyofthoseproductswon'tevenreachtheregionswheretheyaremostneeded.Biotechfirmshaveastrongfinancialincentivetotargetrichmarketsfirstinordertohelpthemrapidlyrecoupthehighcostsofproductdevelopment.Butsomeofthesecompaniesarerespondingtoneedsofpoorcountries.
Moreandmorebiotechresearchisbeingcarriedoutindevelopingcountries.Buttoincreasetheimpactofgeneticresearchontilefoodproductionofthosecountries,thereisaneedforbettercollaborationbetweengovernmentagencies--bothlocalandindevelopedcountries--andprivatebiotechfirms.TheISAAA,forexample,issuccessfullypartneringwiththeUSAgencyforInternationalDevelopment,localresearchesandprivatebiotechcompaniestofindanddeliverbiotechsolutionsforfarmersindevelopingcountries.
Will"Franken-foods"feedtheworld?
Biotechisnotapanacea(治百病的药),butitdoespromisetotransformagricultureinmanydevelopingcountries.Ifthatpromiseisnotfulfilled,therealloserswillbetheirpeople,whocouldsufferforyearstocome.
Theworldseemsincreasinglytohavebeendividedintothosewhofavorgeneticallymodified(GM)foodsandthosewhofearthem.Advocatesassertthatgrowinggeneticallyalteredcropscanbekindertotheenvironmentandthateatingfoodsfromthoseplantsisperfectlysafe.And,theysay,geneticengineering--whichcaninduceplantstogrowinpoorsoilsortoproducemorenutritiousfoods--willsoonbecomeanessentialtoolforhelpingtofeedtheworld'sburgeoning(迅速发展的)population.Skepticscontendthatgeneticallymodifiedcropscouldposeuniqueriskstotheenvironmentandtohealth--riskstootroublingtoacceptplacidly.Takingthatview,manyEuropeancountriesarerestrictingtheplantingandimportationofgeneticallymodifiedagriculturalproducts.Muchofthedebatehingesonperceptionsofsafety.Butwhatexactlydoesrecentscientificresearchsayaboutthehazards?
TwoyearsagoinEdinburgh,Scotland,eco-vandalsstormedafield,crushingcanolaplants.LastyearinMaine,midnightraidershackeddownmorethan3,000experimentalpoplartrees.AndinSanDiego,protesterssmashedsorghumandsprayedpaintovergreenhousewalls.
Thisfar-flungoutragetookaimatgeneticallymodifiedcrops.Buttheprotestsbackfired:
allthedestroyedplantswereconventionallybred.Ineachcase,activistsmistookordinaryplantsforgeneticallymodifiedvarieties.
It'seasytounderstandwhy.Inaway,geneticallymodifiedcrops--nowonsome109millionacresoffarmlandworldwide--areinvisible.Youcan'tsee,tasteortouchageneinsertedintoaplantorsenseitseffectsontheenvironment.Youcan'ttell,justbylooking,whetherpollencontainingaforeigngenecanpoisonbutterfliesorfertilizeplantsmilesaway.Thatinvisibilityispreciselywhatworriespeople.How,exactly,willgeneticallymodifiedcropsaffecttheenvironment--andwhenwillwenotice?
Advocatesofgeneticallymodifiedortransgeniccropssaytheplantswillbenefittheenvironmentbyrequiringfewertoxicpesticidesthanconventionalcrops.Butcriticsfearthepotentialrisksandwonderhowbigthebenefitsreallyare."Wehavesomanyquestionsabouttheseplants,"remarksGuentherStotzky,asoilmicrobiologistatNewYorkUniversity."There'salotwedon'tknowandneedtofindout."
Asgeneticallymodifiedcropsmultiplyinthelandscape,unprecedentednumbersofresearchershavestartedfanningintothefieldstogetthemissinginformation.Someoftheirrecentfindingsarereassuring;otherssuggestaneedforvigilance.
1.Majorityofpeopleinthosecountriesmaintainingalonghistoryofagriculturebelieve______.
A)geneticallymodifiedcropisbeneficial
B)geneticallymodifiedcropcausesenvironmentalproblems
C)high-techcropisagreatbenefittotheworld
D)geneticallymodifiedfoodsisaheatedtopic
这道题您没有回答【回答错误】
答案:
B
[定位]由题干中的majorityofpeoplein...和longhistoryofagriculture可以定位到第一段第二、三句Formanypeople,theconceptofgeneticallyaltered,high-techcropproductionraisesallkindsofenvironmental...Particmlaryincountries...theideaseemsagainstnature.
[精解]题干中的majorityofpeople和文章中的manypeople意思相近;题干中的longhistoryofagriculture意为“悠久的农业历史”,与文章第一段最后一句中的longagrariantraditions意思相同;分析定位句可以得出大多数的人,尤其是有悠久农业历史的国家的人普遍认为转基因作物会引起环境、健康等问题,所以本题答案为B)。
2.HowmuchgeneticallymodifiedcornwasplantedintheUSlastyear?
A)Morethanhalf.B)65millionacres.C)Onethird.D)Threequarters.
这道题您没有回答【回答错误】
答案:
C
[定位]根据题干中的geneticallymodifiedcom和intheUSlastyear可以迅速定位到文章的第二段第二句Athirdofthecom...grownintheUSlastyearweretheproductofbiotechnology,....
[精解]根据定位句可知,去年的转基因玉米的种植面积占到三分之一,转基因大豆和棉花种植面积占到一半多。
因此本题答案应为C)。
3.Whyisthedebateongeneticallymodifiedfoodsmoreheatedindevelopingcountries?
A)Becausetheyhavearichrangeoffoods.B)Becausethesupplyoutstripstheneed.
C)Becausetheyhavetofeedfast-growingpopulations.D)Becausetherisksoutweighthebenefits.
这道题您没有回答【回答错误】
答案:
C
[定位]根据题干中的debateongeneticallymodifiedfoods和heatedindevelopingcountries可以定位到第三段第四句Indevelopingcountriesdesperatetofeedfast-growingandunderfedpopulations...。
[精解]第三段讨论的是发达国家和发展中国家对待转基因食品的态度。
由于发达国家的食品种类丰富并且供过于求,所以debateaboutbiotechistempered(缓和的);而发展中国家人口增长迅速且大多吃不饱,需要大量食品,所以对于是否要采用转基因食品来解决人口和健康问题就显得很迫切。
由此可知C)为本题答案。
4.AccordingtotheUN'sprediction,thegrowthpopulationfromnowto2050isnearlyallin______.
A)westerncountriesB)Africancountries
C)developedcountriesD)developingcountries
这道题您没有回答【回答错误】
答案:
D
[定位],根据题干中的AccordingtotheUN'sprediction,thegrowthpopulationfromnowto2050可以定位到第四段的
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