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ID:21620993
大小:172.50 KB
页数:24页
时间:2018-10-23
《《大学英语(三)》作业》由会员上传分享,免费在线阅读,更多相关内容在教育资源-天天文库。
1、大学英语(三)《大学英语(三)》作业PartI.ReadingComprehensionDirections:Therearethreepassagesinthispart.Eachpassageisfollowedbysomequestions.ForeachofthemtherearefourchoicesmarkedA,B,CandD.Youshoulddecideonthebestchoice.Passage1Inthesummerof1978anEnglishfarmernamedIa
2、nStevenswasdrivinghistractorthroughafieldofwheatwhenhediscoveredsomethingstrange.Someofhiswheatwaslyingflatontheground.Theflattened(被压平的)wheatformedacircleaboutsixmetersacross.Aroundthiscirclewerefoursmallercirclesofflattenedwheat.Inthefollowingyears
3、moreandmoresimilarcircleswerefoundinafieldofwheatorcorn.Sopeoplecannothelpbutaskthequestion:Whatcausesthecircles?Atfirst,peoplesuspectedthatthecircleswereatrick.Toprovethatthecircleswereatrick,peopletriedtocopythem:theytriedtomakecirclesexactlyliketh
4、eonesthefarmershadfound.Theycouldn'tdoit.Theycouldn'tenterafieldofgrainwithoutleavingtracks,andtheycouldn'tflattenthegrainwithoutbreakingit.Thecirclesareapparentlynotatrick.Manypeoplebelievethatbeingsfromouterspacearemakingthecircles.Somethinkthatthe
5、beingsaretryingtocommunicatewithusfromfarawayandthatthecirclesaremessagesfromthem.Othersbelievethatthebeingshaveactuallylandedonearthandthatthecirclesaremarksleftbytheirspaceships.Severaltimespeoplereportedseeingstrangeflyingobjectsnearfieldswherecir
6、cleslaterappeared.Scientistssaythey'renotsurewhatcausesthem.Theyhavesuggestedseveraltheories.Forexample,somescientistssaythat"microbursts"ofwindcreatedthecircles.Amicroburstisadownwardrushofcoolair—thesamedownwardrushofairthatsometimescausesanairplan
7、etocrash.Othersscientistssaythatforceswithintheearthcausethecirclestoappear.Butcirclesoftenappearinforms.Itishardtobelievethatanynaturalforcecouldcreatethoseforms.Andrecentlyfarmershavediscoverednotonlycirclesbutalsoothershapessuchastrianglesintheirf
8、ields.Couldanynaturalforcecreatedaperfecttriangleinafieldofgrain?Inthesummerof1990somescientistsspentthreeweeksinthepartofEnglandwheremanycircleshaveappeared.Theyhadallthelatesthigh-techequipment.Thisequipment—worth1.8milliondollars—recordednothing.B
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