Theageofspacesciencebeganlessthanthirtyyearsago.Butalreadypeoplehavemadegreatdiscoveriesandhavedoneexcitingthings.Theyhavewalkedinspace,visitedthemoon,andlivedinspacelaboratoriesforlongworkingonwaystomakeitposs

　　Theageofspacesciencebeganlessthanthirtyyearsago.Butalreadypeoplehavemadegreatdiscoveriesandhavedoneexcitingthings.Theyhavewalkedinspace,visitedthemoon,andlivedinspacelaboratoriesforlongworkingonwaystomakeitpossibleforpeopletoperiodsoftime.Somescientistsarenowliveonotherplanets.Theyaretryingtosolveproblemsoflivinginspace,eventhoughtheydon’tyetknowwhatalloftheproblemswillbe.Forexample,theydon’tyetknowwhatproblems

　　peoplewouldhaveiftheylovedbeingweightlessforseveralyears.

　　Ifyouwereaspacetraveleryoumighthavetospendseveralmonths,orevenyearsinaspaceship.Whileyouwereintheshipyouwouldn’tliveasyouusuallydo.Youmighthavetofindnewwaystospendyourtime.Yourbodywouldhavetoadjusttodifferentconditions.AndyouwouldhavesomeproblemsthatyouneverthinkabouthereonEarth.Forexample,youwouldhavetohaveahugesupplyoffoodwithyoubecauseyoucan’tgotothesupermarketwhenyou’rehalfwaytoanotherplanet.Youalsowouldneedfreshwaterandawaytogetridofwaste.Infact,therewouldbemanyproblemstosolveinordertoliveinspace.

　　3.Thephrase"ahugesuppleoffood"means_____

　　A.ahugepieceoffood

　　B.thefoodthatislargelysuppliedonthemarket

　　C.alargeamountoffood

　　D.thefoodatthesupermarket

　　4.Whileyouwereinthespaceship,youwouldNOT__

　　A.needfreshwaterandawaytogetridofwaste

　　B.havesomeunusualproblems

　　C.gotothesupermarketwhenyouwerehalfwaytomaotherplanet

　　D.findnewwaystospendyourtime