TOPICREADINGTheInternationalSpaceStation国际空间站是在国际合作基础上建造的最大载人空间站，为人类进行科学研究和天文观测提供了技术保障。TheInternationalSpaceStation(ISS)willbealittle“cityinspace”orbiting(沿轨道运转)250milesabovetheearth.Aboutthesizeoftwofootballfields,thespacestationwillbeaplacewherepeoplefromaroundtheworldcanliveandstudyinspaceoverlongperiodsoftime.TheISSisanextremelyexpensiveproject,butitwillsomedayserveasastepping-stoneforfuturespaceexploration.SixteencountriesfromaroundtheworldareworkingtogetherontheInternationalSpaceStation.TheseinternationalpartnersaretheUnitedStates,Russia,Canada,Japan,BrazilandEuropeanSpaceAgency(Belgium,Britain,Denmark,France,Germany,Italy,theNetherlands,Norway,Spain,Sweden,andSwitzerland).Riskingthedangersofspace,thesixteencountriesarespendingbillionsofdollarsandmanyyearsbuildingthespacestationbecausetheybelievetheycanbenefitalotfromit.Perhapsthemostimportantbenefitisthatthespacestationallowshumanstoliveandstudyforlongperiodsinmicrogravity(微重力),ora“weightless”environment.Thinkofthespacestationasastepping-stonetothestars.Ifhumansareevergoingtotraveltootherplanets,suchasMars,wemustunderstandtheeffectsofsuchlongjourneysonthehumanbody.We’velearnedfrompastspacetravelthatlivinginmicrogravityleadstotheweakeningofbonesandmuscles.Thespacestationwillallowscientiststounderstandtheseeffectsandstudypossiblesolutionsforlong-termspacetravel.Butstudyinginmicrogravityisnottheonlyreasonforthespacestation.Forthefirsttime,wewillbeabletoobservetheearthfromdifferentangles(角度)overlongperiodsoftime.Thespacestationwillallowustowatchchangesintheenvironmenttobetterunderstandourownplanet.Thespacestationwillalsogiveusanopportunitytostudytheenvironmentofspace.Answerthefollowingquestions.1.WhydothesixteencountriesspendalotofmoneybuildingtheInternationalSpaceStation?2.Whatistheeffectoflivinginmicrogravityonhumanbodies?Key:1.Becausetheybelievethebenefitsofthestationwillbegreat.2.Itleadstotheweakeningofbonesandmuscles.
