资料：Upto80percentoftheworld’smiddleclasseswillliveindevelopingcou

资料：Upto80percentoftheworld’smiddleclasseswillliveindevelopingcountriesby2030thankstosurprisingrecentgainsinpovertyreduction,accordingtoaUnitedNationsreportpublishedonThursday. “Neverinhistoryhavethelivingconditionsandprospectsofsomanypeoplechangedsodramaticallyandsofast.”concludestheUN’slatestDevelopmentReport.“Theworldiswitnessinganepochal‘globalrebalancing’.” Underpinningtheimprovementsinthehumandevelopmentindex(HDI)wasrapidgrowthincountriessuchasChina,IndiaandBrazil,withChinaandIndiahavingdoubledpercapitaeconomicoutputinlessthan20years.ButthestudystressedthatgrowthandimprovementsinHDIspreadfarbeyondthefourBriccountriesofBrazil,Russia,IndiaandChina,andincludedatleast40countriesthathadaccompaniedgreatereconomicdynamismwitheffectivepoverty-reductionpolicies. Afghanistan,SierraLeone,Ethiopia,RwandaandAngolawereamong14countriesthathaverecordedgainsinHDIofmorethan2percentayearsince2000.Partlyasaresult,thereportfoundthatworldwideextremeincomepovertyhasplungedfrom43percentin1990tojust22percentin2008,includingmorethan500mbeingliftedoutofpovertyinChinaalone.Thereportstatedthatsuchgainshadalreadyhelpedtheworldachievethemainpovertyeradicationgoaloftheso-calledMillenniumDevelopmentGoals,whichcalledfortheshareofpeoplelivingonlessthan$1.25adaytobecutbyhalffrom1990to2015. Underpinningthispovertyreductionwasdevelopingcountries’increasingshareofglobaltrade,whichgrewfrom25percentto47percentbetween1980and2010.“Thesouthasawholeisdrivingglobaleconomicgrowthandsocietalchangeforthefirsttimeincenturies,”saysthereport. Thereportfoundthattradeamongdevelopingcountrieswasthebiggestfactorinthatexpansion,increasingfromlessthan10percentoftotalglobaltradetomorethan30percent.“Tradebetweencountriesinthesouthwillovertakethatbetweendevelopednations,”thereportsaid. Theword“underpinning”inthepassagerefersto______.

A.blocking

B.undergoing

C.supporting

D.stressing

正确答案是C