21世纪实用英语综合教程2教学课件U8-B.ppt

Unit8 Objectives SuggestedTeachingPlan BackgroundInformation ClassPresentation Preview Preview ThisisthelastunitofBookTwo IntheListeningandSpeakingsection youwilllearnhowtoaskforandgivereasons IntheReadingandWritingsection youwillreadthreepassagesaboutscienceandtechnology TextAwaswrittenattheturnofthe21stcenturyandthewriterpredictedthetopfivescientificdevelopmentsofthecomingcentury TextBconcernsissuesofsafetythatmustbeguaranteedwhenthefrontierofscienceandtechnologyisbeingpushedback PracticalReadingisaformthatpeopleneedtofilloutuponarrivalintheU S prev Objectives Afterstudyingthisunit thestudentsareexpectedtobeableto Obj masterthebasiclanguageandskillsnecessarytoaskforandgivereasons 1 understandthemainideasofTextsAandB andmastertheusefulsentencestructuresandwordsandexpressionsfoundintheexercisesrelevanttothetexts 2 3 knowhowtouseV ingphrases V edphrasesandToVphrasesasadverbials 4 knowhowtowriteanemail 6 understandparagraphdevelopment 5 5 readaformthatpeopleneedtofilloutuponarrivalintheU S SuggestedTeachingPlan SuggestedTimeandTeachingPlanforUnit8 Time Contents Plan 1 TheLanguageforAskingForandGivingReasons Giveabrieflead intalkonthenatureandusesofaskingforandgivingreasons A s t p 1 TheteacherbeginswiththePreviewtomakesurethatthestudentshaveageneralideaofwhatthisunitisallabout Afterthat theteacheractivateslisteningandSpeakingexercisesasfollows 2periods Preview ListeningandSpeaking B PresentthenecessarylanguagebydoingExercise1 C Askonestudenttoreadaloudthetalksostudentscanchecktheircompletedanswers D OrganizeanactivityforEx 2thatwillreinforcetheusefullanguagestudentspickedupinEx 1 Time Contents Plan s t p 1 2 2 ThePracticeofAskingForandGivingReasons GothroughthenewwordsinthefirstconversationinEx 3 A B Havethestudentslistentotheconversationtwiceandfillintheblankswiththemissingwords C Askthemtoanswerthequestionsabouttheconversation D Tellthemtolookforthelanguageusedtoaskingforandgivingreasons Time Contents Plan s t p 2 Askthestudentstorole playtheconversation Havethemlistentothesecondconversationtwiceandcompletetheshortpassageaccordingly F E Suggesttheydiscusseachoftheircompletedanswersinordertogainabetterunderstandingoftheconversation G Now havethemlistentotheconversationagainandcompletetheformasthespeakerrecountsit H Afterwards havethemchecktheirresponsesbyactingouttheconversation I Time Contents Plan s t p 3 3 ListeningPractice Beforeending theteachertellsthestudentstodoEx 5 10astheirassignmenttoreviewthefunctionalandnotionallanguagepickedupintheListeningandSpeakingsection TheteacheralsotellsthemthattheyshouldbepreparedtoanswerthequestionsinExercise9andgiveanoralpresentationinclasswhentheynextmeet OrganizeauniqueclassroomactivityforEx 4thatwillreinforcetheusefullanguagestudentspickedupearlierintheunit J 3periods Reviewofthelisteningandspeakingskillsthestudentshavelearned Theteacherbeginswithareviewofthefunctionalandnotionallanguagethestudentspickedupinthepreviousclasses TheteacherasksseveralstudentstoanswerthequestionsinEx 9oftheListeningandSpeakingsection andinvitesafewtosharewiththeirclassmatestheiropinionsonthetopic Itismoreimportanttoraisequestionsthantoanswerthem Then theteacherturnstotheReadingandWritingsection Theseactivitiesshouldbecompletedin15minutes s t p 4 Time Contents Plan 1 Starter Afterabriefexplanationoftheinstructions theteacher A givesthestudentsafewminutestothinkaboutthequestionsinthestarter s t p 5 Time Contents Plan B askssomestudentstoanswerthequestions 2 TextA A Theteacher letsthestudentsanswerthetext relatedquestions helpsthemidentifythemainideaofeachparagraph andanalyzessomedifficultsentencesandsomelanguage TextA text relatedexercises B guidesthestudentsthroughtheexercises focusingoncertainitemsorleavingsomeexercisesasthestudentshomeworkaccordingtothestudentsdifferentlevelsofEnglish oneperiod s t p 8 1period GrammarReview 1 GrammarReview TheteachertalksabouttheuseofV ingphrases V edphrasesandToV phrasesasadverbials andatthesametimeasksthestudentstodothegrammarexercisesinclass Time Contents Plan pointswhilediscussingthewholetextwiththestudents oneandahalfperiods s t p 9 PracticalWriting 2 PracticalWriting TheteacherexplainstothestudentshowtowriteanemailbydoingEx 12ofPracticalWriting andthenrequiresthestudentstodoEx 13andEx 14afterclass Time Contents Plan s t p 10 2periods TextB Text relatedexercises 1 TextB Whilediscussingthetextwiththestudents theteachercallsonthemtopayattentiontothestructureoftheparagraphsofthetext introducingbrieflytheconceptofthetopicsentence Ex 16andEx 17canbedoneeitherinorafterclass 2 PracticalReading Thispartshouldeitherbereadbythestudentsthemselvesastheirhomeworkordoneinclass Time Contents Plan PracticalReading s t p 11 BasicReadingSkills 3 BasicReadingSkills Theteacherexplainstothestudentsparagraphdevelopment 5 andasksthemtodotheexercisesinBasicReadingSkills Time Contents Plan BackgroundInformation JamesTrefil OriginalTextof TheTop5ScientificBreakthroughsofthe21stCentury BI ModernScience 20thcentury ThreeMileIsland TheChernobylAccident Radiationsickness SovietUnionandRussia BI JT JamesTrefil Asanaward winningauthorandphysicist JamesTrefilhaswrittenmorethan25booksonarangeofsciencetopics He sacontributortoNationalPublicRadioandSmithsonianMagazine andaphysicsprofessoratVirginia sGeorgeMasonUniversity U S A OriginalTextof TheTop5ScientificBreakthroughsofthe21stCentury The20thcenturyproducedscientificandtechnologicalchangeatadizzyingpace greaterthaninanyothercenturyinhistory Butthe21stcentury thedawnofthenewmillennium maywellseeevenmoredramaticchangedrivenbyadvancesinscienceandtechnology Onthesepagesaremypredictionsforthetopscientificdevelopmentswe llseeinthenext100years intheorderIthinkthey llhappen BI OT1 其中提及了作者进行预测的根据 JamesTrefil BI OT2 1 We llknowwherewecamefromWhydoestheuniverseexist Toputitanotherway whyistheresomethinginsteadofnothing Sincethe1920s scientistshaveknowntheuniverseisexpanding whichmeansitmusthavestartedatadefinitetimeinthepast Theyevenhavedevelopedtheoriesthatgiveadetailedpictureoftheevolutionoftheuniversefromthetimeitwasafractionofasecondoldtothepresent Overthenextcoupleofdecades thesetheorieswillberefinedbydatafromextraordinarilypowerfulnewtelescopesandadvancesinourunderstandingofhowmatterbehavesattheunfathomablyhightemperaturesandpressuresoftheearlyuniverse BI OT2 MargaretGelleroftheHarvard SmithsonianCenterforAstrophysics apioneerinexploringthestructureoftheuniverse believesthat by2100 wewillhaveacompletemapofallthegalaxiesinthevisibleuniverse ConsideringthatthefirstprimitivemapsofNorthAmerica producedbyexplorerswhofollowedColumbus appearedonly500yearsago amerecenturytomapeverygalaxywithin15billionlight yearsofEarthseemsabreathtakingaccomplishment BI OT3 2 We llcrackthegeneticcodeandconquercancerIn19th centuryoperas whentheheroinecoughsinthefirstact theaudienceknowsshewilldieoftuberculosisinAct3 Butthanksto20th centuryantibiotics theonce dreaded once incurablediseasenowcanmeannothingmoreseriousthantakingsomepills Asscientistslearnmoreaboutthegeneticcodeandthewaycellsworkatthemolecularlevel manyseriousdiseases cancer forone willbecomelessthreatening Usingmanufactured therapeutic viruses doctorswillbeabletoreplacecancer causingdamagedDNAwithhealthygenes probablyadministeredbyapillorinjection BI OT3 FrenchAndersonoftheUniversityofSouthernCaliforniaMedicalSchool whodidthefirstgene therapytreatmentonahuman predictsthat in15or20years themajorityofdiseaseswillbetreatableinthisway Bytheendofthenextcentury peoplewilllookatourfearofcancerthewaywenowlookattheoperaticfearofTB asaquaintrelicofanimmaturetechnology BI OT4 3 We lllivelonger 120years Ifthenormalagingprocessisbasicallyafurious invisiblecontestinourcells acontestbetweendamagetoourDNAandourcells abilitytorepairthatdamage then21st centurystridesingeneticmedicinemayletuscontrolandevenreversetheprocess Expertsinthisfielddistinguishbetweenincreasinglongevity extendingtheaveragelifespan now76 5yearsintheUnitedStates aswehavebeendoingforcenturies andincreasingthemaximumpossiblelifespan whichseemstobeabout120years Nodoubtwecanachievethefirst butexpertsarereluctanttospeculateaboutthesecond SaysRitaEffrosoftheUCLASchoolof BI OT4 Medicine aleadingresearcheronagingandtheimmunesystem Ithink120yearsofgoodhealthisenoughforanyone Sobeforewepushscientiststodomore consider Dowereallywanttoliveinaworldwherenoonegrowsoldand presumably fewchildrenarebornbecausetheplanetcanholdonlysomanypeople Wherewouldnewideascomefrom Whatwouldwedowithallthatextratime Andwouldyoureallywanttobeadeputyassistantmanagerfor500years BI OT6 4 We ll manage EarthInthenextmillennium we llstoptalkingabouttheweatheranddosomethingaboutit DavidTilmanoftheUniversityofMinnesota apioneerindevelopingandtestingecologicaltheories says Theworld secosystemsareincrediblycomplex andthejobofunderstandingthemismadeharderbythefactthattheyarebeingchangedbytheinfluenceofhumanbeings Aswebuildbiggerandfastercomputers however themysteryandunpredictabilitywillstarttofade BI OT6 We llgraduallylearnhowtopredicttheeffectsofhumanactivityontheEarth itsclimateanditsecosystems Andwiththatknowledgewillcomeanincreasingwillingnesstouseittomanagetheworkingsofourplanet Earthwillbemanaged likeafarmoragamepreserve TheDutchhavebeendoingthissortofthingonasmallerscaleforcenturiesinmanagingtheirsystemofdikes Iseenoreasonhumanityorganizedinaglobalvillagecan tdothesame BI OT5 5 We llhaveabrain roadmap Thisisthereal finalfrontier ofthe21stcentury Thebrainisthemostcomplexsystemweknow Itcontainsabout100billionneurons roughlythenumberofstarsintheMilkyWay eachconnectedtoasmanyas1 000others Earlyinthenextcentury wewilluseadvancedformsofmagneticresonanceimagingtoproducedetailedmapsoftheneuronsinoperation We llbeabletosaywithcertaintywhichonesareworkingwhenyoureadaword whenyousayaword whenyouthinkaboutaword andsoon BI OT7 StevenPinkeroftheMassachusettsInstituteofTechnology notedpsychologistandauthorofthebookHowtheMindWorks predictsthatinthenextcentury we lllearnalotaboutthingswedon tunderstandtoday humanemotions socialrelationships reasoninganddecision making We llseenewtreatmentsforspecificmentalconditions astoday sProzactreatsdepression We lldevelopmedicinesthatenhancementalfunctions likethesteroidsathletesusetopromotemusclegrowth butwithouttheharmfulsideeffects Sowiththisfifthpredictionwecomefullcircle andrealizethatthemostdifficultthingtounderstandintheuniversemaybethe3 poundorganwecarryaroundinourskulls theorganthatallowsustounderstandtheuniverseinthefirstplace BI MS1 ModernScience 20thcentury Inthe20thcentury scientistsachievedspectacularadvancesinthefieldsofgenetics medicine socialsciences technology andphysics 1 GeneticsAtthebeginningofthe20thcentury thelifesciencesenteredaperiodofrapidprogress Mendel sworkingeneticswasrediscoveredin1900 andby1910biologistshadbecomeconvincedthatgenesarelocatedinchromosomes thethreadlikestructuresthatcontainproteinsanddeoxyribo nucleicacid DNA Duringthe1940sAmericanbiochemistsdiscoveredthatDNAtakenfromonekindofbacteriumcouldinfluencethecharacteristicsofanother Fromtheseexperiments itbecameclearthatDNAisthechemicalthatmakesupgenesandthusthekeytoheredity BI MS2 AfterAmericanbiochemistJamesWatsonandBritishbiophysicistFrancisCrickestablishedthestructureofDNAin1953 geneticistsbecameabletounderstandheredityinchemicalterms Sincethen progressinthisfieldhasbeenastounding Scientistshaveidentifiedthecompletegenome orgeneticcatalog ofthehumanbody seeHumanGenomeProject Inmanycases scientistsnowknowhowindividualgenesbecomeactivatedandwhateffectstheyhaveinthehumanbody Genescannowbetransferredfromonespeciestoanother side steppingthenormalprocessesofheredityandcreatinghybridorganismsthatareunknowninthenaturalworld seeTransgenicOrganism BI MS3 2 MedicineAttheturnofthe20thcentury DutchphysicianChristiaanEijkmanshowedthatdiseasecanbecausednotonlybymicroorganismsbutbyadietarydeficiencyofcertainsubstancesnowcalledvitamins In1909GermanbacteriologistPaulEhrlichintroducedtheworld sfirstbactericide achemicaldesignedtokillspecifickindsofbacteriawithoutkillingthepatient scellsaswell Followingthediscoveryofpenicillinin1928byBritishbacteriologistSirAlexanderFleming antibioticsjoinedmedicine schemicalarmory makingthefightagainstbacterialinfectionalmostaroutinematter Antibioticscannotactagainstviruses butvaccineshavebeenusedtogreateffecttopreventsomeofthedeadliestviraldiseases Smallpox onceaworldwidekiller wascompletelyeradicatedbythelate1970s andintheUnitedStatesthenumberofpoliocasesdroppedfrom38 000inthe1950stolessthan10ayearbythe21stcentury BI MS4 Bythemiddleofthe20thcenturyscientistsbelievedtheywerewellonthewaytotreating preventing oreradicatingmanyofthemostdeadlyinfectiousdiseasesthathadplaguedhumankindforcenturies Butbythe1980sthemedicalcommunity sconfidenceinitsabilitytocontrolinfectiousdiseaseshadbeenshakenbytheemergenceofnewtypesofdisease causingmicroorganisms Newcasesoftuberculosisdeveloped causedbybacteriastrainsthatwereresistanttoantibiotics New deadlyinfectionsforwhichtherewasnoknowncurealsoappeared includingthevirusesthatcausehemorrhagicfeverandthehumanimmunodeficiencyvirus HIV thecauseofacquiredimmunodeficiencysyndrome Inotherfieldsofmedicine thediagnosisofdiseasehasbeenrevolutionizedbytheuseofnewimagingtechniques BI MS5 includingmagneticresonanceimagingandcomputedtomography Scientistswerealsoonthevergeofsuccessincuringsomediseasesusinggenetherapy inwhichtheinsertionofnormalorgeneticallyalteredgenesintoapatient scellsreplacesnonfunctionalormissinggenes Improveddrugsandnewtoolshavemadesurgicaloperationsthatwereonceconsideredimpossiblenowroutine Forinstance drugsthatsuppresstheimmunesystemenablethetransplantoforgansortissueswithareducedriskofrejection seeMedicalTransplantation Endoscopypermitsthediagnosisandsurgicaltreatmentofawidevarietyofailmentsusingminimallyinvasivesurgery Advancesinhigh speedfiber opticconnectionspermitsurgeryonapatientusingroboticinstrumentscontrolledbysurgeonsatanotherlocation Knownastelemedicine thisformofmedicinemakesitpossibleforskilledphysicianstotreatpatientsinremotelocationsorplacesthatlackmedicalhelp BI MS6 3 SocialSciencesInthe20thcenturythesocialsciencesemergedfromrelativeobscuritytobecomeprominentfieldsofresearch AustrianphysicianSigmundFreudfoundedthepracticeofpsychoanalysis creatingarevolutioninpsychologythatledhimtobecalledthe Copernicusofthemind In1948theAmericanbiologistAlfredKinseypublishedSexualBehaviorintheHumanMale whichprovedtobeoneofthebest sellingscientificworksofalltime Althoughcriticizedforhismethodologyandconclusions Kinseysucceededinmakinghumansexualityanacceptablesubjectforscientificresearch BI MS6 The20thcenturyalsobroughtdramaticdiscoveriesinthefieldofanthropology withnewfossilfindshelpingtopiecetogetherthestoryofhumanevolution AcompletelynewandsurprisingsourceofanthropologicalinformationbecameavailablefromstudiesoftheDNAinmitochondria cellstructuresthatprovideenergytofuelthecell sactivities MitochondrialDNAhasbeenusedtotrackcertaingeneticdiseasesandtotracetheancestryofavarietyoforganisms includinghumans BI MS7 4 TechnologyInthefieldofcommunications ItalianelectricalengineerGuglielmoMarconisenthisfirstradiosignalacrosstheAtlanticOceanin1901 AmericaninventorLeeDeForestinventedthetriode orvacuumtube in1906 Thetriodeeventuallybecameakeycomponentinnearlyallearlyradio radar television andcomputersystems In1920ScottishengineerJohnLogieBairddevelopedtheBairdTelevisor aprimitivetelevisionthatprovidedthefirsttransmissionofarecognizablemovingimage Inthe1920sand1930sAmericanelectronicengineerVladimirKosmaZworykinsignificantlyimprovedthetelevision spictureandreception In1935BritishphysicistSirRobertWatson Wattusedreflectedradiowavestolocateaircraftinflight RadarsignalshavesincebeenreflectedfromtheMoon planets andstarstolearntheirdistancefromEarthandtotracktheirmovements seeRadarAstronomy BI MS8 In1947AmericanphysicistsJohnBardeen WalterBrattain andWilliamShockleyinventedthetransistor anelectronicdeviceusedtocontroloramplifyanelectricalcurrent Transistorsaremuchsmaller farlessexpensive requirelesspowertooperate andareconsiderablymorereliablethantriodes Sincetheirfirstcommercialuseinhearingaidsin1952 transistorshavereplacedtriodesinvirtuallyallapplications Duringthe1950sandearly1960sminicomputersweredevelopedusingtransistorsratherthantriodes Earliercomputers suchastheelectronicnumericalintegratorandcomputer ENIAC firstintroducedin1946byAmericanphysicistJohnW MauchlyandAmericanelectricalengineerJohnPresperEckert Jr usedasmanyas18 000triodes BI MS8 andfilledalargeroom Butthetransistorinitiatedatrendtowardmicrominiaturization inwhichindividualelectroniccircuitscanbereducedtomicroscopicsize Thisdrasticallyreducedthecomputer ssize cost andpowerrequirementsandeventuallyenabledthedevelopmentofelectroniccircuitswithprocessingspeedsmeasuredinbillionthsofasecond Furtherminiaturizationledin1971tothefirstmicro processor acomputeronachip Whencombinedwithotherspecializedchips themicroprocessorbecomesthecentralarithmeticandlogicunitofacomputersmallerinsizethanaportabletypewriter Withtheirsmallsizeanda BI MS9 pricelessthanthatofausedcar today spersonalcomputersaremanytimesmorepowerfulthanthephysicallyhuge multimillion dollarcomputersofthe1950s Onceusedonlybylargebusinesses computersarenowusedbyprofessionals smallretailers andstudentstoperformawidevarietyofeverydaytasks suchaskeepingdataonclients trackingbudgets andwritingschoolreports Peoplealsousecomputerstointerfacewithworldwidecommunicationsnetworks suchastheInternetandtheWorldWideWeb tosendandreceivee mail toshop ortofindinformationonjustaboutanysubject BI MS10 Duringtheearly1950spublicinterestinspaceexplorationdeveloped ThefocaleventthatopenedthespaceagewastheInternationalGeophysicalYearfromJuly1957toDecember1958 duringwhichhundredsofscientistsaroundtheworldcoordinatedtheireffortstomeasuretheEarth snear spaceenvironment Aspartofthisstudy boththeUnitedStatesandtheSovietUnionannouncedthattheywouldlaunchartificialsatellitesintoorbitfornonmilitaryspaceactivities WhentheSovietUnionlaunchedthefirstSputniksatellitein1957 thefeatspurredtheUnitedStatestointensifyitsownspaceexplorationefforts In1958the BI MS10 NationalAeronauticsandSpaceAdministration NASA wasfoundedforthepurposeofdevelopinghumanspaceflight Throughoutthe1960sNASAexperienceditsgreatestgrowth Amongitsachievements NASAdesigned manufactured tested andeventuallyusedtheSaturnrocketandtheApollospacecraftforthefirstmannedlandingontheMoonin1969 seeApolloProgram Inthe1960sand1970s NASAalsodevelopedthefirstroboticspaceprobestoexploretheplanetsMercury Venus andMars seeMariner ThesuccessoftheMarinerprobespavedthewayfortheunmannedexplorationoftheouterplanetsinEarth ssolarsystem Inthe1970sthrough1990s NASAfocuseditsspaceexplorationeffortsonareusablespaceshuttle whichwas BI MS11 firstdeployedin1981 In1998thespaceshuttle alongwithitsRussiancounterpartknownasSoyuz becametheworkhorsesthatenabledtheconstructionoftheInternationalSpaceStation 5 PhysicsIn1900theGermanphysicistMaxPlanckproposedthethensensationalideathatenergyisnotinfinitelydivisiblebutisalwaysgivenoffinsetamounts orquanta Fiveyearslater German bornAmericanphysicistAlbertEinsteinsuccessfullyusedquantatoexplainthephotoelectriceffect whichisthereleaseofelectronswhenmetalsarebombardedbylight This togetherwithEinstein sspecialandgeneraltheoriesofrelativity challengedsomeofthemostfundamentalassumptionsoftheNewtonianera BI MS12 Unlikethelawsofclassicalphysics quantumtheorydealswitheventsthatoccuronthesmallestofscales Quantumtheoryexplainshowsubatomicparticlesformatoms andhowatomsinteractwhentheycombinetoformchemicalcompounds Quantumtheorydealswithaworldwheretheattributesofanysingleparticlecanneverbecompletelyknown anideaknownastheuncertaintyprinciple putforwardbytheGermanphysicistWernerHeisenbergin1927 Butwhilethereisuncertaintyonthesubatomiclevel quantumphysicssuccessfullypredictstheoveralloutcomeofsubatomicevents afactthatfirmlyrelatesittothemacroscopicworld thatis theoneinwhichwelive BI MS12 In1934Italian bornAmericanphysicistEnricoFermibeganaseriesofexperimentsinwhichheusedneutrons subatomicparticleswithoutanelectriccharge tobombardatomsofvariouselements includinguranium Theneutronscombinedwithth