E The need to feed a growing population is putting much pressure on the world’s supply of

E

Theneedtofeedagrowingpopulationisputtingmuchpressureontheworld’ssupplyofwater.With97%oftheworld’swatertoosaltytobedrunkorusedinagriculture,theworldwidesupplyofwaterneedscarefulmanagement,especiallyinagriculture.Althoughtheideaofawatershortage（短缺）seemsstr angetosomeonefortunateenoughtoliveinahighrainfullcountr y,manyoftheworld’sagriculturalindustr iesexperienceconstantwatershortages.

Althoughdamscanbebuilttostorewaterforagriculturaluseindryareasanddryseaons,thecostsofwaterredistr ibution(重新分配)areveryhigh.Notonlyistherethecostoftheengineeringitself,butthereisalsoanenvironmentalcosttobeconsidered.Wherevalleys(山谷)arefloodedtocreatedams,housesarelostandwildlifehomesdestr oyed.Besides,watermanyfloweasilythroughpipestofields,butitcannotbetr ansportedfromonesideoftheworldtotheother.Eachcountr ymustthereforerelyonthemanagementofitsownwatertosupplyitsfarmingrequirements.

Thisisparticularlytr oublingrocountr ieswithagriculturalindustr iesinareasdependentonirrigation（灌溉）.InTexas,farmers’overuseofirrigationwaterberesultedina25%redcutionofthewaterstores.IntheCentr alValleyareaofsoutheasternUSA,ahugewaterengineeringprojectprovidedwaterforfarmingindryvallege,butmuchofthewaterusehasbeenpoorlymanaged.

SaudiArabia’sattemptstogrowwheatindesertareashavebeenthepumpingofhugequantitiesofirrigationwaterfromundergroundreserves.Becausethereisnorainfallintheseareas,suchreservescanonlydecrease,anditisbelievedthatfiftyyearsofpumpingwillseethemrundry.

72.Fromthefirsttwoparagraphswelearntthat_______.

A.muchoftheworld’swaterisavailableforuse

B.peopleinhighrainfllcountr iesfeellucky

C.thecostsofwaterredistr ibutionshouldbeconsidered

D.watercanbeeasilycarriedthroughpipesacrosstheworld