题目内容：
根据以下材料回答题 Withhumanfootprintsonthemoon,radiotelescopeslisteningformessagesfromaliencrea-tures(whomayormaynotexist),technicianslookingforcelestialandplanetarysourcesofenergytosupportourcivilization,orbitingtelescopes'datahintingatplanetarysystemsaroundotherstars,andpoliticalgroupstryingtofigureouthowtosavehumanityfromnuclearwarfarethatwoulddamagelifeandeliminateonaplanet-widescale,anastronomybookpublishedtodayentersaworlddifferentfromtheonethatgreetedbooksagenerationago．Astronomyhasbroadenedtoin-volveourbasiccircumstancesandourmysteriousfutureintheuniverse．Witheclipsesandspacemissionsbroadcastlive,andwithNASA,Europe,andtheUSSRplanningandbuildingpermanentspacestations,astronomyoffersadventureforallpeople,anoutwardexploratorythrustthatmayonedaybeseenasanalternativetomindlessconsumerism,ideologicalbickering,andwarstocon-troldwindlingresourcesonaclosed,finiteEarth．
Today'sastronomystudentsnotonlyseekanup-to-datesummary,ofastronomicalfacts:theyask,aspeoplehaveaskedforages,aboutourbasicrelationstotherestoftheuniverse．Theymaystudyastronomypartlytoseekpointsofcontactbetweenscienceandotherhumanendeavors:phi-losophy,history,politics,environmentalaction,eventheartsandreligion．
Sciencefictionwritersandspecialeffectartistsonrecentfilmshelptoday'sstudentsrealizethatunseenworldsofspacearerealplaces--notabstractconcepts．Today'sstudentsarecitizensofamorereal,morevastcosmosthanconceptualizedbystudentsofadecadeago．
Indesigningthisedition,theWadsworheditorsandIhavetriedtorespondtothesedevelop-ments．Ratherthanjumpingatthestartintomurkywatersofcosmology,IhavebegunwiththeviewpointofancientpeopleonEarthandworkedoutwardacrosstheuniverse．Thismethodofor-ganizationautomatically(ifloosely)reflectstheorderofhumanity'sdiscoveriesaboutastronomyandprovidesaunifyingthemeofincreasingdistanceandscale．
Thispassageismostprobablytakenfrom A．anarticleofpopularscience．
B．theintroductionofabookofastronomy．
C．alecturegivenbytheauthortoastronomystudents．
D．theprefaceofapieceofsciencefiction．
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