The Population Bomb.docx

The Population Bomb.docx

《The Population Bomb.docx》由会员分享，可在线阅读，更多相关《The Population Bomb.docx（15页珍藏版）》请在冰豆网上搜索。

ThePopulationBomb

UNIT8

TextA

PRE-READINGTASK

Exercise1

Beforereadingthepassage,trytoanswerthequestions.

1.Howmanyyearsdoyouthinkittakestodoubletheworldpopulationnow?

2.Whatmightbethepossiblesolutionstothepopulationexplosionintheworld?

Nowcompareyouranswerswithyourneighbours'.

ThePopulationBomb

I.Toomanypeople

1Figureandnumerousfactsprovethattherearealready,andcertainlythattherewillbe,toomanypeople.Simplycalculatingthelengthsoftimenecessarytodoubletheworld'spopulationisinstructive.Impressively,thetimerequiredgrowsevershorter:

6000yearsbeforeChrist,1000000yearswerenecessarytodoublethepopulation,thenabout1650yearsafterChristonly1000aroundthe1850's200years,in193080years.Currently,theworld'spopulationdoublesevery37years.

2Whatwouldhappenifthepopulationweretocontinuedoublinginvolumeevery37years?

3Accordingtorecentcalculations,maintainingsucharhythmofgrowthwouldresultin60millionbillionpeopleontheearthin900years,whichrepresents120inhabitantspersquaremeter.

4Optimistsbelieveandoftenassertthatsciencewillindeedfindsolutionstotheproblemofovercrowding,namelybyprovidingthemeanstoimmigratetootherplanets.Butthissolutionistotallyimpossible.Ineffect,evenifitshouldbecomepossible,50yearswouldbesufficientforthe60millionbillionpersonstomultiplytothepointofpopulatingVenus,Mercury,Mars,theMoonandthesatellitesofJupiterandSaturnwithadensityequaltothatoftheEarth.

II.FoodShortage

5Today,agoodpartofhumanitysuffersfrommalnutritionorfromundernourishment.

6Somethinkthattherecentscientificdiscoveriesappliedtoagricultureandknownunderthenameof"greenrevolution"willresolvetheproblem.Nothingislesscertain.Promotersoftherevolutionthemselvesbelievethatitcanofferonlyarespiteoftenortwentyyears.

7Inunderdevel-opedcountries,al-thoughmostlyagri-cultural,thelaginfoodproductioninrelationtopopulationgrowthincreasesmoreandmore.Asthecrisisworsensthesecountrieswillhavetoimportfood.Butfromwhere?

III.ADyingPlanet

8Theworld'spopulationexplosionisthesourceofawholeseriesofenvironmentaldeteriorations,whichintimecanhavedisastrousconsequences.

9Becausethepopulation-foodimbalancemakesitnecessarytoincreaseagriculturalproduction"atanyprice",methodsoftenharmfultotheenvironmentareusedwithoutjudgment.Forexample,theconstructionofhugedamstoirrigatehundredsofthousandsofacrescaninfactprovokecatastrophes.Thus,theAswanDamcurrentlypreventsthedepositoffertilesiltsbroughteachyearbythefloodingoftheNile.TheresultwillobviouslybeadecreaseinthefertilityoftheDeltalands.DammingtheMekongrisksthesameconsequencesforVietnamandneighbouringcountries.

10Fertilizers,syntheticpesticides,DDTcanbedevastating,transformingcomplexecosystems,necessaryfortheconservationoftheenvironment,intosimpleecosystems.

11Certainsituationsareperceivedasdangerousonlywhentheybecomecriticalenoughtocausenumerousdeaths.Smogisanexample.InLondonin1952itcausedsome4000deaths.Thisincidentprovokedanawakeningofconscienceandresultedindecisionswhichhaveproveneffective.Butsmogpresentsstillotherdangers:

namely,itdestroysplantswhichofferlittleresistance,andwhoseoxygenproductionisindispensabletous,anditchangestheearth'sthermalequilibrium.

12Fortheseformsofpollutionasforalltheothers,thedestructivechainofcauseandeffectgoesbacktoaprimecause:

"toomanycars,toomanyfactories,toomanydetergents,toomanypesticides,moreandmoretrailsleftbysupersonicjets,inadequatemethodsfordisinfectingsewers,toolittlewater,toomuchcarbonmonoxide.Thecauseisalwaysthesame:

toomanypeopleontheearth."

NewWords

numerous

a.many许多的,众多的

instruct

v.1.教，教育

2.通知，向…提供事实情况

instructive

a.1.有启发的，有教益的

2.教育的，指导性的

impressive

a.causingadmirationbygivingoneafeelingofimportance给人以深刻印象的

impressively

ad.给人以深刻印象地

namely

ad.（and）thatis（tosay）即，那就是

immigrate

v.tocomeintoacountrytomakeone'slifeandhomethere移居，移入

multiply

v.toincrease增加

populate

v.（ofagroup）tolivein（aparticulararea）（大批地）居住于，生活于

satellite

n.1.aheavenlybody,movingaroundalargerone卫星

2.aman-madeobjectintendedtomovearoundtheearth,moon,etc.人造卫星

density

n.1.密集，稠密

2.密度

undernourishment

n.营养不足

respite

n.（ashortperiodof）pauseorrest,duringatimeofgreateffort,pain,ortrouble暂缓，暂停

lag

n.aperiodoftimebywhichsomethingisslowerorlater落后，滞后

worsen

v.to（causeto）becomeworse变得更差，恶化

deterioration

n.thestateofbecomingworse恶化，变坏

judgment

n.theabilitytojudgecorrectly判断

dam

n.awallorbankbuilttokeepbackwater坝，堤

v.tobuildadamacross筑坝

irrigate

v.tosupplywaterto（dryland）灌溉

acre

n.ameasureofland,about4047squaremetres英亩（≈4047平方米）

provoke

v.tocause引起

catastrophe

n.asudden,unexpected,andterribleeventthatcausesgreatsuffering灾难

fertile

a.（ofland）whichproducesgoodcrops肥沃的

silt

n.（水流夹带或水底沉积的）泥沙，淤泥

fertility

n.theconditionorstateofbeingfertile肥沃，丰产

delta

（河流的）三角洲

synthetic

a.1.合成的

2.综合的

pesticide

n.农药，杀虫剂

transformv.tochangecompletelyinform,appearance使改变（性质等）

ecosystem

n.生态系统

awakening

n.theactofbecomingconsciousorconcerned觉醒，唤醒

resistance

n.theabilityorpowerofresisting抵抗力

oxygen

n.氧，氧气

indispensable

a.thatistooimportanttolivewithout必不可少的

destructive

a.破坏性的，毁灭性的

detergent

n.achemicalproductusedforcleaning洗涤剂

trail

n.aseriesofmarksleftbyapersonorthingpassingby痕迹

supersonic

a.fasterthanthespeedofsound超音速的

adequate

a.sufficient充分的，足够的

inadequate

a.notadequate不适当的，不充分的

disinfect

v.消毒，杀菌

carbon

n.碳

monoxide

n.一氧化物

PhrasesandExpressions

ineffect

实际上，实质上

beequalto

等于，比得上

underthenameof

名叫，称为

sufferfrom

遭受

inrelationto

与…相比，与…有关，涉及

intime

最终，迟早，及时

atanyprice

不惜任何代价

ProperNames

beforeChrist

公元前

Venus

金星

Mercury

水星

Mars

火星

Saturn

土星

theAswanDam

阿斯旺水坝

theNile

尼罗河

theMekong

湄公河

Vietnam

越南

DDT

滴滴涕（商品名，一种杀虫剂）

TextB

PRE-READINGTASK

Exercise1

Beforereadingthepassage,thinkaboutthequestions.

1.Whatwoulditbelikeiftherewerenotreesontheearth?

2.Whyisitimportantforustoplantmoretreesnowadays?

Nowreadthepassageandcheckyouranswerswiththeauthor's.

ReforesttheEarth!

1Throughoutthedrought-riddensummerof1988,theworldheardmuchabouthowtheburningoffossilfuelscausesthegreenhouseeffect（therapidwarmingoftheearth'satmosphere.）Weheardlittleabouthowtheburningoftropicalrainforestsalsocontributestothegreenhouseeffect.Andstilllessdowehearabouthowreforestationofthesetropicscouldhelphealanailingworld.

2Theearthconstantlymaintains700billionmetrictonsofcarbondioxide（CO2）intheatmosphere.Fossilfuelsemitanother5.2billionmetrictonsofCO2intotheaireachyear,whiletheburningoftropicalforestsemitsroughly1.8billionmetrictonsofCO2--bothcontributingtoabuildupofcarbondioxidethatwillsoontriggerthegreenhouseeffect.TheCO2gasestraptheheatofthesuninthesamewaytheglassofagreenhousecontrolstemperatureforplants.Ifthegasesbecometooconcentrated,toomuchheatwillcollect,resultinginrisingtemperatures.

3Ofallthecarbondioxideemittedintotheatmosphere,onlyabouthalfaccumulatesintheskieswhiletherestdisappearsintooceansandlakes,vegetationandsoil.Sooutofthe5.2billionmetrictonsofCO2emittedfromtheburningoffossilfuelsandthe1.8billionmetrictonsreleasedfromtheburningofrainforestseachyear,only3.5billionmetrictonscontributestoglobalwarming.

4In1980,36000squaremilesofforestwereburnedinthetropics.In1987,33000squaremilesofrainforestwereburnedinBrazilianAmazoniaalone.Bytheyear2020thefigurefortropical-forestemissionsofCO2couldclimbtoanother5billionmetrictons.Asaresult,theCO2releasedintotheatmosphereeachyearwouldrisetoapproximately10.2billionmetrictons.

5Replantingtreesinthetropicscouldeventuallyofferasolutiontothegreenhouseeffect.Atreeabsorbscarbondioxidethroughphotosynthesis.Plantenoughtrees（asmanyas250billion）andwecouldremovemuchoftheadditionalCO2buildingupintheatmosphere.Nowhereintheworldareconditionsbetterforgrowingtreesthaninthetropics,whereyear-roundwarmthandmoistureencouragerapidgrowth.Tostartagrand-scaletree-growingprojectinthetropics,however,wouldrequireasmanyas20governmentsinLatinAmerica,Africa,andAsiatostoptherapiddestructionofrainforests.

6Howmanytreeswouldweneedtoreforesttheearthandstabilizethedamageproducedbyglobalwarming?

Oneacreofatropicalplantationcanabsorbanannualaverageoffourmetrictonsofatmosphericcarbon.Inordertosoakup1billionmetrictonsofCO2,wewouldhavetoplant400000squaremilesofnewtropicalforests.Toeliminatethebuildupof3.5billionmetrictonswouldrequireplantingtreeson1.2millionsquaremiles,anexpanseroughlyequivalenttoallstateseastoftheMississippi.

7Wherecanwefindenoughspacetoreplantwhatisn'tbeingotherwiseutilized?

Inthehumidtropicsforestshavebeencutdowninwatershedregionswherereplantingisurgentlyneededtostop