TheUNpassedaruleintheyear2004toimprovethequalityofdrinkwaterandreducedeathscausedbydrinkingunhealthywatereachyear.TheUNhasalreadyworkedoutthespecificplantoreducehalfofthenumberthatisfivethousand.

TheUNpassedaruleintheyear2004toimprovethequalityofdrinkwaterandreducedeathscausedbydrinkingunhealthywatereachyear.TheUNhasalreadyworkedoutthespecificplantoreducehalfofthenumberthatisfivethousand.TheUNannouncedintheworldthereareabout1/6oftheworldpopulationcan'tmeetthesanitationregulationofdrinkingwater.

Thewaterwedrinkanduseisrunningshortintheworld.Weallhavetolearntostopwastingourquitelimitedwater.Oneofthestepsweshouldtakeistofindwaysofreusingit.Experimentshavealreadybeendoneonthisfield.Todayinmostlargecitiesfreshwaterisusedonlyoncethenitrunsintowastesystem.Butitispossibletopipetheusedwatertoapurifying(净化)factory.Thereitcanbefiltered(过滤)andtreatedwithchemicalssothatitcanbeusedagainjustasitwerefreshfromaspring.Butevenlargecitiespurifiedandreuseditswaterwestillwouldnothaveenough.Thenwecouldturntotheoceans.Allwewouldhavetodotomakeuseofseawateronearthistogetthesaltoutofit.Thismethodhasalreadybeenusedinmanypartsoftheworld.

47.Thewaytostopwastingwateristo________.

A.doexperimentswithwater

B.purifytheusedwaterandreuseit

C.usefreshwateronceagain

D.makeuseofseawater

48.Thepassagetellsushowtoreusetheusedwater.Whichistherightorderoftheprocess?

a.tohavetheusedwaterfilteredb.toputchemicalinit

c.topipeittotheuser

d.topipetheusedwatertobepurifiedinafactory.

A.dabcB.bcdaC.bdcaD.dcba

49.Therewouldn'tbeenoughwaterforusifwedidn't________.

A.turntotheoceanformorewater

B.reuseusedwaterandmakeuseofseawater

C.makefreshwaterfromtheseawater

D.takestepstoreuseallwateronearth

50.Theword"it"underlinedinthelastparagraphrefersto________.

A.theprocessofcollectingsaltfromtheocean

B.theprocessofgettingridofthesaltinseawater

C.purifiedwater

D.seawater