Unit3languageinuse,grammar,vocabulary,sentences,Contentofourpassage,地球火星木星行星太陽系星系宇宙,Earth,Mars,Jupiter,planet,Solarsystem,galaxy,universe,V.,discovershowgrowcostpreferexplore,discovered,discovered,showed,showed,grew,grown,cost,cost,preferred,preferred,explored,explored,Thedialogueinunit1,Thepassageinunit2,Openyourmouthandsaysomething,Thepresentperfecttense:,Structure:,have/has+p.p.,already,just,yet,before,ever,Nicky:Ihavejust_(see)agreatTVprogrammeaboutspace.Didyouknowthatscientistshave_(discover)wateronMars?Bill:No!Really?Thatisveryinteresting._they_(try)tofindlifeonMars?Nicky:Well,theyarelookingforlifebutthey_(notfind)anythingyet.Bill:Theyhavealready_(find)thatthereisnolifeonthemoon.Nicky:Yes,thatisright.SofarthereisonlylifeinEarth,seen,discovered,Have,tried,haventfound,found,have/has+goneto,Theastronautshavegonetothespacestation.,Theyhavegonethere,buttheyhaventcomeback.,have/has+beento,Theastronautshavebeentothespacestation.,Theywentthereandthemtheycameback,Usehave/hasgonetoandhave/hasbeentotocompletethesentences.,1.Astronauts_tothemoonandreturnedsafely.,2.Thespacecraft_intospace.Itwontreturn.,3.Thespaceshuttle_tothespacestation.Itwillcomebacktomorrow.,havebeen,hasgone,hasgone,3.Aspacecraft_toMars.Itscomingbacktoearthnextyear.,4.Lotsofastronauts_tothespacestation.Theyfounditveryinteresting.,5.SomeAmericanastronauts_tothemoonseveraltimes,6.ABritishastronaut_tothespacestation.HellcomebackinJanuary.,hasgone,havebeen,havebeen,hasgone,DearDiary,Ive(1)_finishedreadingagreatbookatschool.Ihavent(2)_anythingasgoodasthatforalongtime!Itisabookaboutthesolarsystem.ItissogoodthatIve(3)_askthelibrarytokeepthenextbookforme!Inthebook,itsaysthatthatastronautshave(4)_toMarsandeventoJupiter(5)_readthatbefore!Ithinktheyrekeepingitsecret!,just,read,already,been,never,I(6)_metanyonefamousinmylifebutIhopeonedayIllmeetarealastronaut.Ive(7)_toNASAtoaskthemformoreinformationaboutastronauts