阅读理解 Passage4 ShouldtheUnitedStatessupporta“ManInSpace”program?Opponentsandproponent spresentstrongargumentsonbothsides. Theopponentspointouthowenormouslyexpensivemannedspaceoperationsare:Everyshuttleflightcoststaxpayersabout$500million,andtheanticipatedbillfortheinternationalspacestationis$35billion-$40billion.Theyalsothinkthatthereturnsfromsuchspaceinvestmentssofardonotjustifytheexpense.TheysuspectthatmuchofthespacetestingofnewmaterialsandpurercrystalscouldbeperformedonEarthatamuchlowercost,eitherthroughautomatedsystems,onless-expensiveunmannedrockets,oreveninlaboratories.Theybelieveitisrecklesstospendsuchenormoussumsofmoneyinspaceforanuncertainreturn,whentherearesomanyunmetneedshereonEarth. Theproponentsofmannedspaceprogramshavedifficultycounteringthesestrongarguments.However,theypointoutthatsincethespaceshuttlenowexistswemightaswellmakeuseofit.TheybelievethatnewmaterialscreatedinthespaceenvironmentmayproveextremelyusefulandthattheperfectcrystalswhichcannotbemadeinEarth’sgravitywillallowustounderstandthemolecularstructureofviruses.Asaresult,wemaybeabletocreatepowerfulnewdrugs,perhapsovercomingcriticaldiseases,evenAIDS.Theyalsoarguethatthespacestationrepresentsthefirsttrulyinternationalendeavoronagreatscaleandthatitwillpromotecooperationandunderstandingbetweennationsandhelpeliminatefuturewars. Takingabroaderview,thereisnodoubtthatexplorationofnewlandsandconquestsofnewfrontiershavealwaysbeencreativeforcesthroughoutthehistoryofhumanityandhavepromotedtheadvancementofknowledgeandculture.In1993,whenCongresssavedtheinternationalspacestationfrombeingabandoned,adecisiveeventoccurredinman’sconquestofspace.Thiscriticalactmaydeeplyaffecthumanity’sfuture.ItwasthediscoveryoftheNewWorldthatgaveWesterncivilizationtheimpetusfortheexplosivegrowthinscienceandtechnologythattookplaceduringthesucceedingcenturies.Exploringspaceandcolonizingotherplanetsisnotanoption.Itisanecessityifhumanityistoevolveandnotbecomeaninactivespecieswithnoroomandnoincentiveforfurtherdevelopment.