新视野大学英语视听说第4册听力原文及答案Unit8.doc
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Uint8
II.BasicListeningPractice
1.Script
M:
Scentistsclaimtheworldpopulationhas99.5%ofthesameDNA.
W:
Butthisdoesn’ttellusthereisnosuchthingasrace.
Q:
WhatistrueoftheDNAofdifferenceraces?
2.Script
W:
Withtheadventofthegeneticmapweknowwhereeverythingis,butdoweknowwheretogowithit?
M:
Yourmapseemstodifferlargelyfrommygeographicalmap!
Q:
Whatdoesthemanimply?
3.Script
M:
Asyouknow,ithastakenmillionsofyearsofevolutionandnaturalselectiontogetuswherewearetoday.
W:
Yes,butnowthatwehavegeneticengineering,weseemtohavedecidedthatwewanttobeGod.
Q:
Whatdoesthewomanimply?
4.Script
M:
Ithinktheresearchintocloningwillleadusintodangers,fillinguswithfalsehopesofperfection.
W:
It’stoolatetoturnbacktheclock.We’lljusthavetodependoncommonsensetosolveuncommonproblems.
Q:
Whatdoesthewomanmean?
5.Script
W:
InAmerica,manyprisonersarehavingtheircasesreviewed,andsomehaveevenbeenfreedthroughDNAtesting.
M:
Exceptfortheoneswhosedeathsentencehasalreadybeencarriedout.
Q:
WhatcanwelearnaboutDNAtestingfromthedialog?
Keys:
1.B2.C3.D4.A5.C
III.ListeningIn
Task1:
StemCellResearch
Script
Gregory:
TheRepublicanpartyinAmericaisopposingstemcellresearch.Ifindit
hardtobelievethatinthisdayandage,someonewoulddothat.
Lillian:
Stemcellresearchsoundsprettyimpressive,I’lladmit.Butjustwhatisit?
Gregory:
Well,astemcellisaspecialtypeofcell.Itisageneralcellthat,whenit
devides,canbecomeanyspecifictypeofcell.
Lillian:
Youmean,astemcellcanbecomeaheartcell?
Orabrainorakidneycell?
Gregory:
That’saboutit.Stemcellsareapartofthebody’smaintenanceandrepair
system.Whentheydivide,theycanbecomeanycelltype.
Lillian:
Iguesstherewouldbesometremendousmedicaladvantagesinthatsortof
research.
Gregory:
You’vesaidamouthful.Recently,scientistswereabletohelpamanwho
lostajawboneforcancer.Theyrecreatedbonematerialforhisjawfromstemcells.Whatitmeansisthatsincethenewbonewascreatedoutoftheperson’sowncells,therewasnoproblemwithrejectionbecausetheDNAwasthesame.
Lillian:
Ibetthepersonwasdelighted.Whywouldanyoneopposethatsortofresearch?
Itwouldseemtohaveendlesspotentialtobenefitthehumanrace.
Gregory:
Iagree,buttherearepeoplewhothinkweshouldnotinterferewithnatureandmanipulate“whatisnatural”.
Lillian:
It’seasiertoholdsuchanarrowviewifyou’renotinapositiontoneedthebenefitsoftheresearch.Ifyou’remissingajawbonebecauseofcancer,youprobablysupporttheresearch.
1.Whatisthepassagemainlyabout?
2.Whoisagainststemcellresearch?
3.Whatisspecialaboutastemcell?
4.Whencanastemcellbecomeanothercelltype?
5.Accordingtothepassage,whydosomepeopleopposestemcellresearch?
Keys:
1.B2.A3.A4.A5.D
Task2:
TheImprovementofRice
Script
Scientistsnowknowalotmoreaboutagrainthatpeoplehaveeatenfortenthousandyears.（S1）Researchteamsaroundtheworldhavecompletedamapofthe（S2）genesofrices.Thefindingsappearedlastweekinthe（S3）journalNature.
Theaimistospeeduptheimprovementofrice.Thescientists（S4）warnthatthekindsofriceplantsusednowhavereachedthelimitoftheir（S5）productivity.Yetworldriceproductionmust（S6）growbyanestimated30percentinthenexttwentytomeetdemand.By2025,asmanyas4.6billionpeoplewilldependonricefor（S7）survival.Thereisalotofpressureonbreederstoimprovethecrop,andthericegenomeisavaluabletooltodothat.（S8）Plantbreedershavealreadyusedpreliminaryinformationfromthericegenometocreateexperimentalstrainsofricethatbetterresistcoldandpests.
Theresearchersalsosayriceisanexcellentchoiceforgeneticmappingandengineering.Ricegeneshaveonlyabout390millionchemicalbases.Thatmaightsoundlikealot.Butothermajorfoodgrainshavethousandsofmillions.（S9）Thenewmapcouldbetterexplainmorethanjustrice.Ricesharesacommonancestorwithothercerealcrops.Becausericeisthefirstcerealcroptobefullyanalyzed,researchersexpectthatsufficientknowledgeofitsgeneticinformationwillrevealtheheredityofmorecomplexgrains,includingcorn,wheatandbarley.
（S10）Whilesignificantprogresshasbeenmadeintheanalysisofthericegenome,themappingofhumangenesisalsomakingheadway.Whenscientistscanidentifyandmanipulategenesthatcausecertaindiseases,mankindwillcurethemeasily.Thehumangeneticmapmayhelpuscontrolaperson’sheight,weight,appearanceandevenlengthoflife.
Ta
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