[托福]历年托福考试阅读真题汇总含答案

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1、0308托福试题阅读（55minutes）Question1-11Iffoodisallowedtostandforsometime,itputrefies.Whentheputrefiedmaterialisexaminedmicroscopically,itisfoundtobeteemingwithbacteria.Wheredothesebacteriacomefrom,sincetheyarenotseeninfreshfood?Evenuntilthemid-nineteenthcentury,manypeoplebelievedthatsuch

2、microorganismsoriginatedbyspontaneous(5)generation,ahypotheticalprocessbywhichlivingorganismsdevelopfromnonlivingmatter.ThemostpowerfulopponentofthetheoryofspontaneousgenerationwastheFrenchchemistandmicrobiologistLouisPasteur(1822-1895).Pasteurshowedthatstructurespresentinairclosel

3、yresemblethemicroorganismsseeninputrefyingmaterials.Hedid(10)thisbypassingairthroughguncottonfilters,thefibersofwhichstopsolidparticles.Aftertheguncottonwasdissolvedinamixtureofalcoholandether,theparticlesthatithadtrappedfelltothebottomoftheliquidandwereexaminedonamicroscopeslide.P

4、asteurfoundthatinordinaryairtheseexistsavarietyofsolidstructuresranginginsizefrom0.01mmtomorethan1.0mm.Manyofthesebodiesresembledthereproductive(15)structuresofcommonmolds,single-celledanimals,andvariousothermicrobialcells.Asmanyas20to30ofthemwerefoundinfifteenlitersofordinaryair,a

5、ndtheycouldnotbedistinguishedfromtheorganismsfoundinmuchlargernumbersinputrefyingmaterials.Pasteurconcludedthattheorganismsfoundinputrefyingmaterialsoriginatedfromtheorganizedbodiespresentintheair.Hepostulatedthatthesebodiesareconstantly(20)beingdepositedonallobjects.Pasteurshowedt

6、hatifanutrientsolutionwassealedinaglassflaskandheatedtoboilingtodestroyallthelivingorganismscontaminatingit,itneverputrefied.Theproponentsofspontaneousgenerationdeclaredthatfreshairwasnecessaryforspontaneousgenerationandthattheairinsidethesealedflaskwasaffectedinsomeway(25)byheatin

7、gsothatitwouldnolongersupportspontaneousgeneration.Pasteurconstructedaswan-neckedflaskinwhichputrefyingmaterialscouldheheatedtoboiling,butaircouldreenter.Thebendsintheneckpreventedmicroorganismsfromgettingintheflask..Materialsterilizedinsuchaflaskdidnotputrefy.1,Whatdoesthepassagem

8、ainlydiscuss?(a)Pasteur’si