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一个不透明的盒子里装有除颜色外其他都相同的红球6个和白球若干个，每次随机摸出一个球，记下颜色后放回，摇匀后再摸，通过多次试验发现摸到红球的频率稳定在0.3 左右，则盒子中白球可能有（ ）
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在一个不透明的口袋中装有5个红球4个白球3个黄球它们除颜色外都相同从中任意摸出一个球摸到红球的概率是
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在一个不透明的口袋中装有5个红球3个白球它们除颜色外都相同从中任意摸出一个球摸到红球的概率为.
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一个不透明的口袋里装有红白黄三种颜色的乒乓球除颜色外其余都相同其中有白球2个黄球1个红球3个.若从中
一个不透明的盒子中装有3个红球2个黄球和1个绿球这些球除颜色不同外其他均相同.从中随机摸出一个球恰好
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一个不透明的盒子里装有3个红球和6个白球它们除颜色外都相同从中任意摸出一个球摸到红球的概率为．
一个不透明的口袋里装有红白黄三种颜色的乒乓球除颜色不同外其余都相同其中有2个白球1个黄球.若从中任意
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一个不透明的盒子中装有5个红球和3个白球它们除颜色外都相同.若从中任意摸出一个球则下列叙述正确的是▲
摸到红球是必然事件；
摸到白球是不可能事件；
摸到红球和摸到白球的可能性相等；
摸到红球比摸到白球的可能性大；
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10个
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摸到白球是不可能事件
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摸到红球比摸到白球的可能性大
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HowtoStrengthenTeethNaturally1.Youcanworkonstrengtheningyourteethbygettingtherightvitaminsandmineralsinyourdiet.Youcanalsoprotectyourteeththroughhealthyhabits.Inadditionavoidingcertainfoodsandhabitscanhelpstrengthenyourteeth.◆Gettherightnutrients营养Makesureyou'regetting1000to1200mgofcalcium钙aday.Youprobablyknowcalciumhelpskeepyourbonesstrong.2Eatingcertainamountofcalciuminyourdieteverydaywillhelpincreasethestrengthofyourteeth.◆3.Aimtoeatawidevarietyoffruitsandvegetablesinyourweeklydiet.Tryselectingavarietyofcolorswhenchoosingyourproduceasthatensuresyou'llbegettingawidevarietyofvitamins.Fillyourplateuphalfwaywithfruitsandvegetablesateverymealthenfilltherestofyourplatewithsomeproteinandwholegrains.◆BrushyourteethtwiceadayTobrushwellholdyourtoothbrushata45℃angletoyourteeth.Brushallthesurfacesofyourteethgentlyandtrytobrushforatleast2minutes.4.◆VisityourdentistregularlyVisityourdentistatleastonceayearforx﹣raysandcleaning.5Ifyoustarttogetabuildupofplaque牙菌斑whichcanweakenteeththedentistcanremoveitforyouintime.◆QuitsmokingYouprobablyareawarethatsmokingcauseslungcancerandotherhealthproblems.Inadditionitcanalsoweakenbonetissueincludingyourteeth.Ifyou'vebeenthinkingaboutquittingnowmaybethetime.A.Thesevisitshelpfindproblemsbeforetheybegin.B.Thesefoodsnaturallycleanyourteethhelpingtokeepthemstrong.C.EatabalanceddietD.Thesameistrueforyourteeth.E.Setatimertohelpyoubrushlonger!F.VitaminDhelpsyourbodyabsorbcalciumproperly.G.Strongteethareimportantforahealthymouth!
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马的毛色由两对同源染色体上的等位基因控制其中一对同源染色体的相同基因位点在种群中有AtAa三种基因称为复等位基因相关表现型与基因组成的关系如表．如图是某育种场繁育马的系谱图请回答 1Ⅰ1Ⅰ2的基因型分别为． 2复等位基因AtA和a之间的显隐性关系是At对显性A对显性． 3Ⅱ1与Ⅱ3杂交后代中骝色马出现的几率为． 4如果要鉴定Ⅱ2的基因型可以让其与系谱中的杂交若杂交后代出现骝色马则Ⅱ2的基因型是若杂交后代出现褐骝色马则Ⅱ2的基因型是．
ToooftenalearnerofEnglishwhohasreadoneortwoclassicstriestoimitate模仿theirstyle.Thefacthoweveristhatstylecannotbeimitated.Differentauthorshavedifferentstyles.Theydonottrytowritethewaytheywrite.Sotheimitationofanystyleoftenresultsinaffectation矫揉造作. Andtheresultwillbetillworseifthestyleimitatedisthatofaworkwrittenahundredyearsagoormore.Weareofthe21stcenturyandweshouldnotwritetheEnglishofthelastcentury. Iwouldadviseyounottoaimataspecialstyle.TakecaretowritecorrectsimpleidiomaticandclearEnglishthat'sall. Butimitationisnotalwaysbad.Veryoftenitisimportanttoimitatesomething.Wherepersonalstyleisoutofplaceimitationistheonlymeansbywhichcorrectnessmaybesecured.Inwritinganadvertisementaboutsomethingforexampleyouhavetoimitatesomesuchadvertisementthatyouhaveread.Youcannotpossiblywriteagoodoneifyouhaveneverreadanythoughyoumayhavereadverywidelyingeneralliterature. Youwilldowelltocollectanumberofshortadvertisementsformalinvitationsannouncementsandbusinesscontractsetc.Whenyouhaveoccasiontowriteoneofsuchyouhavesimplytodoalittleimitatingandadapting.Thefollowingisanordinaryformalinvitation Mr.andMrs.M.S.AdamsrequestthepleasureofMr.andMrs.L.J.Williams'scompanyatdinneronSaturdayeveningMaytheseventeenthatseveno'clock86StarStreet. ThisinvitationisfromMr.andMrs.M.S.AdamstoMr.andMrs.L.J.Williams.Surelywiththispiecebeforeyouyoucanwriteanewone.Youhavesimplytochangethenamesthedaythedatethetimeandtheaddress. 1Whyisitespeciallywrongtoimitatethestylecenturiesago? A.Becausethelanguageisoutofdate. B.Becausethewritershavepassedaway. C.Becausethestyleisdifficulttofollow. D.Becausethecontentsarebehindthetimes. 2What'stheauthor'sattitudetowardsimitation? A.Englishlearnersshouldneverimitateothers'writingstyle. B.ImitationisthefirststepforEnglishlearnerstowritearticles. C.Englishlearnersshouldimitateformalwritingstyleslikeadvertisements. D.Itisalwayscorrectforlearnerstoimitatetheclassicwritingstyles. 3Whatdoesthewritermostprobablydo? A.Heisaprofessorinuniversity. B.HeisanEnglishteacher. C.HeisanEnglishnovelist. D.Heisaclassictranslator.
ShemustbethewisestwomanonthisplanetforshehasliveduptothethreewordsSeizethemoment.Toomanypeopleputoffsomethingthatbringsthemjoyjustbecausetheyhaven'tthoughtaboutitorbecausetheyareunwillingtotrysomethingnew. Mysisterdiedafewyearsago.Weneverdidhavelunchtogether.Ican'trememberhowmanytimesIwasrefusedwhenIcalledhertogotolunch.ShewouldsaytomeIcan't.Ihaveclothesontheline.Myhairisdirty.IwishIhadknownyesterday.Ihadalatebreakfast.Itlookslikerain.OnlyafterherdeathdidIchoosetobealittlemoreflexible. Lifeisnotmadeupofthingsthatyoudoataparticulartimebutitdemandsvarietyandadventure.Aswegrowolderthelistofpromisesmadetoourselvesmaygetlonger.PerhapsonemorningwhenweawakenwewillfindtooursurprisethatourlifeisfullofI'mgoingtoIplantoandSomedaywhenthingsaresettleddownabit. Myseizethemomentfriendisopentoadventureandreadyatanymomenttomakeanewstart.Shekeepsanopenmindaboutnewideas.Hergreatinterestinlifeiscontagious.Withheraroundyouyoumaytradeyourbadfeetforgoodshoes. Ihavenottouchedicecreamfor10years.TheotherdayIstoppedoffandboughtatripledecker.IfmycarhadhitanicebergonthewayhomeIwouldhavediedhappy. 1Thepassagesuggeststhattheauthor'ssister. A.wasverybusywithherwork B.diedaveryhappyperson C.alwaysdidthingsinafixedorder D.wasthewisestwomanintheworld 2Thewriterhashadanewwayoflookingatlifesince. A.hissisterdied B.hemetthewisewoman C.heturnedold D.thethreewordsappeared 3Theunderlinedwordcontagiousinthefourthparagraphisusedtoshowthatthewomanis. A.polite B.powerful C.practical D.proud 4Theauthorexpectsthosewhohavereadthepassageto. A.havealonglistofpromises B.beasmartbusinessman C.hitanicebergintheircars D.beasadventurousashimself
若图1图2图3是某同学做有丝分裂实验时在光学显微镜下观察到的图象下列有关说法正确的是
中国科学家成功突破了克隆猴这个世界生物学前沿的难题率先建立起可有效模拟人类疾病的动物模型实现了我国在非人灵长类研究领域由国际“并跑”到“领跑”的转变．据此冋答下列问题 1克隆猴的诞生体现了动物细胞的具有全能性．相对于植物组织培养而言动物尤其 是高等动物的克隆比较困难的原因最．克隆过程中一般利用未受精的去核卵细胞作为受体细胞原因是． 2克隆猴培养过程中需要用葡处理使细胞从瓶壁上分离下来．为了提高动物细胞克隆形成率可以选择适宜的培养基添加等天然成分以滋养细胞支持生长．培养箱中通常要维持一定的CO2浓度CO2的作用是．克隆猴除了用到动物细胞工程的相关生物技术手段外还必须用到答出两种技术．
UniversityStudentLifeinNorthAmericaFormanywesternersgoingtouniversityisaveryexcitingtimeinlife.1Otherstudentschoosetoliveawayhomeeveniftheygotoauniversitythatisclosetotheparents'house.Thisisusuallythefirsttimethatyoungpeopleliveawayfromtheirparentsandbegintheiradultlives.2Theybelieveitgivesthestudentanopportunitytofacemanynewexperienceswithoutthehelpoftheirparents.Mostwesternershavetheopinionthatagooduniversityeducationneedsabalanceofhardstudyingdoingextra﹣curricularactivitiesanddoingsomefunsocialthingssuchasgoingdancingwithfriends.Oftenstudentsfindaromanticlove.Itiscommontoseetwolovershandinhandastheywalkdownthestreet.3Generallyuniversitiesalsodonotmindifstudentsdate.Inthefirstyearofuniversitystudentsusuallyliveinresidencewheretheymeetpeople.Mostresidenceroomsaredoubleroomswheretwostudentsshareoneroom.Sometimesstudentscangetsingleroomsiftheyarelucky.4Inthesehouseseachstudenthastheirownbedroombutusuallysharesabathroomkitchenandlivingroomwithotherstudents.Itisgettingmoreandmorecommontohavegirlsandboyslivinginthesamehouse.Inthewestuniversitieshavemanyextra﹣curricularactivitiesthatstudentscanchoosefrom.5Iftheyarenotyourthingthenyoucandophotographyartdramaormanyotherthings.Inshortstudentsinwesternuniversitieshavealotoffunfreedomandinterestingexperiences.Workingoutisbecomingamoreandmorepopularactivity.A.Studentscanplaymanydifferentsports.B.Studentsliketogotothegymtoworkout.C.Mostpeoplechoosetogotoauniversitythatisfarawayfromhome.D.Itiscommonforastudenttomoveintoastudent'shousewithfriends.E.Parentsinthewestusuallydonotmindiftheirchildhasfoundalove.F.Manywesternershavefuntryingtostayhealthyandexercisetheirbodies.G.Mostparentsconsidertheirchildleavinghomeforuniversitytobeagoodthing.
关于生物变异的叙述正确的是
Alistofthetopsevennaturalwondersisrecognizedbymostorganizations.Twoofthemostcommonlylistednaturalwonders1findbelowsealevel.OneofthesewondersistheGreatBarrierReefs.TheotherisBrazil'sHarborofRioDeJanerio.Itisnotonlythebiggestbay2baseontheamountofwaterinitbutalsobecauseofthesurroundingmountainsandrockformations.Twomoreoftheworld'swondersarerelatedtorivers.Bothwondersarenottheriversthemselves3whatiscreatedbyeachriver.OneistheGrandCanyon4iscutthroughthelandscapeofthesouthernUnitedStatesbytheColoradoRiver.Anotheroftheworld'swonderisVictoriaFalls.Itistheworld's5largewaterfallrankedbytheamountofwater6flowoverit.Thenexttwowondersofthenaturalworld7bemountains.ParicutinisavolcanoinMexico.Thereasonwhythisvolcanohasbeenvotedisthatpeopleactuallywatcheditsbirthand8growinthe1940s.ThenOfcoursetheworld'stallestmountainMt.Qomolangmashouldbeadded9thelistofnaturalwonders.Unliketheothersixnaturalwonders10seventhnaturalwonderAuroraBorealiscannotbeseenallthetimeasitcomesandgoesfromdaytoday.
排乳是指哺乳或挤乳时反射性地引起贮存在腺泡和乳腺导管系统内的乳汁迅速排出体外的过程．如图表示排乳的部分调节过程．回答下列问题 1排乳过程的调节方式是．下丘脑细胞合成的催产素能运至垂体并暂时贮存暂时贮存的生理意义是． 2在排乳过程中泌乳素与催产素之间具有作用．泌乳素能作用于乳腺腺泡细胞是由于其细胞膜上分布有． 3催乳师通过按摩能解决产妇无乳乳少等问题据图分析其原因是．
阅读下面短文根据所给情节进行续写使之构成一个完整的故事. Mymomonlyhadoneeye.Ihatedher.Shewassuchanembarrassment. Sheranasmallshopatafleamarketandcollectedoldclothesandsomeotherthingstosellforthemoneyweneeded.Onceduringelementaryschoolitwasfielddayandmymomcame.Iwassoembarrassedandwonderedhowcouldshedothistome?Ithrewherahatefullookandranout.ThenextdayatschoolmyschoolmatesaskedmeYourmomonlyhasoneeye?andlaughedatme. Iwassoangrywithmymomandwishedthatshewouldjustdisappearfromthisworld.SoIsaidtomymomWhydon'tyouhavetheothereye?You'reonlygonnamakemeajoke!MymomtrembledwithshockandsaidinanapologetictoneI'msosorrythatIonlyhaveoneeyeandIwasanembarrassmentforyou.ButIwassoproudofmysontoseeawholenewworldformewiththateye.Iwillleaverightnow.Sorry!Mymomturnedaroundandstaggeredaway. ForthewordsIhadsaidtoherearliertherewassomethingbitingatmeinthecornerofmyheart.EvensoIhatedmyone﹣eyedmomandourdesperatepoverty.Maybebecausemymomhadn'tpunishedmeIdidn'tthinkIhadhurtherfeelingsverybadly. ItoldmyselfthatIwouldbecomesuccessfulinthenearfuturesoIstudiedveryhard.LaterIgotacceptedbytheSeoulUniversity.IleftmymotherandcametoSeoultostudy.Ineverwentbacktovisitmymom. ThenIgotmarriedthere.Iboughtahouseofmyown.ThenIhadkidstoo.NowIamlivinghappilyasasuccessfulman.IenjoythelifeinSeoulbecauseit'saplacethatdoesn'tremindmeofmymomandmypast.Thiskindofhappinesswasgettingbiggerandbiggeruntilonedaysomeoneknockedatmydoor. 注意 1.所续写短文的词数应为150左右 2.应使用5个以上短文中标有下划线的关键词语 3.续写部分分为两段每段的开头语已为你写好 4.续写完成后请用下划线标出你所使用的关键词语. Para1Itwasmymom!Andstillwithheroneeye! Para2HoldingtheletterIcriedforthepersonwhoonlylivedforme.
Weallputoffthingsinonewayoranotherfinishingafinalpaperhoursbeforethedeadlineorputtingoffthattriptothesupermarketuntiltherefrigeratorshelvesarecompletelyempty.Psychologistscallthatprocrastinationwhichistodelaydoingsomethingthatyoushoulddousuallybecauseyoudon'twanttodoit. Inrecentyearspsychologistsaroundtheworldhavebeenaskingwhatelseistherebehindprocrastination?ProcrastinationisbasedonourgeneticssaysSharadPaulMDauthorofTheGeneticsofHealth.Ifyouliketoputthingsofforsurftheinternetinsteadofgettingworkdoneyoumightbeabletoblameyourancestors. Whileprocrastinationseemslikeacharacterweaknessitdevelopedforareason.Thegenesprogresseddowngenerationsbecausethesepeoplewerestillhiddenincavesfearfulofanimalsthatfedon meat.Theywerealwayssaying‘Mytoolsarenotsharpenough.I'dbetterspendmoretimeperfectingthisspear.'saysSharadPaul.Thesepeoplesurvivedmorebecausetheyavoidedconflictsandthesegeneswerehandeddowntofuturegenerations. Whileit'shighlyattractivetosimplyblameyourparentsthebuckstopswithyou.PaulsaysPeoplethinkthatgenesdeterminetheirfate.Thisisonlytrueiftheiractionsleadinthatdirection. AnythingcanbechangedorimprovedincludingourgeneexpressionssaysPaulwholikestorefertothe10000﹣hourstheoryMalcomGladwellsharesinhisbookTheOutlierssuggestingthattalentismadewithpracticeandcommitmentnotaborncharacter.Thebestthingtoovercomeprocrastinationistogetmoving.Startslowandkeepbuildingupperseverancelevels.Therearemanydifferentformsofperseveranceexerciseandmanyinvolvelegmovements.Pickonethatyoulike.Anaverageofjust30minutesadayhasbeenshowntobebeneficial. PaulsaysIfyouhavetherightgenesthiscouldbeperhapsabitfasterbutnotbymuch.Thereforethereishopeforusall. 1Whydoestheauthoruseexamplesinthefirstparagraph? A.Tomakereadersfamiliarwiththemselves. B.Tointroducethetopicofprocrastination. C.Toshowourbadbehavioursofprocrastination. D.Toexplainwhywehavethehabitofprocrastination. 2Theunderlinedsentenceinparagraph4probablymeans. A.Genesfromyourparentsaretoblame. B.Youractionsmakeyouhighlyattractive. C.Youshouldtaketheresponsibilityforyourself. D.Youshouldstopthrowingbucksatyourparents. 3What'sbesttitleofthepassage? A.GenesWeaknessorHope? B.GenesPreventionorCure? C.ProcrastinationReasonandSolution. D.ProcrastinationExampleandHistory.
Pattidiscoveredthemeaningofrunningwhenshewas23.Atthattimeshewassmokingtwopacksofcigarettes香烟adayandhad1weight﹣﹣﹣over30pounds.'Idecidedto2'shesays.Shetookaclockandstarted3whatshedideverydayandthenshe4anhouradayasa'benicetoPattihour'.'Istartedhavingbubble泡沫bathswith5litbecauseCosmopolitanMagazine6thatthiswouldbegoodforme.ButIgot7ofthatsoon'Pattiremembers.Shewantedtodosomethingreallypleasant.Shefoundthatthe8timesinherlifeweretimeswhenshewasphysicallyactive.Soshetookup9.Shedecidedtostart10thenextday.Sheranforanhour11atotalof7milesonherfirstrun.'Icouldn'twalkfortwoweeks12Ifeltpainfulallover!'Pattirecalls回忆.'ButIfeltsowonderful!'Pattiwasn'tcrazyaboutrunningyetbutshewasin13withtheaftereffectsofrunning.WithinsevenmonthsPattihadrunherfirstmarathonqualified有资格的fortheBostonMarathonandplaced25thintheworldfor14distancerunners.Overthenextyearsshe15recordsandsetstandardsforwomeninthesport.ShewasthefirstAmericanwomantoruna230marathonandthenbroke16tworecords17an8﹣monthperiod.Patti18thatifwecansetstandardsforourselveswecanpullourselvesoutofthemostdifficult19andcomeoutontop.'Everybodyhastobeachampionand20hasthatinthem.'1A.lost B.earned C.gained D.reduced2A.cry B.move C.walk D.change3A.striking B.recording C.sharing D.collecting4A.setaside B.setup C.setout D.setabout5A.lamps B.fires C.candles D.cigarettes6A.spoke B.said C.wrote D.went7A.afraid B.fond C.tired D.ashamed8A.saddest B.happiest C.loneliest D.luckiest9A.smoking B.bathing C.dieting D.running10A.right B.only C.even D.again11A.covering B.spreading C.passing D.overcoming12A.but B.although C.while D.because13A.peace B.line C.love D.touch14A.men B.women C.adults D.children15A.kept B.held C.broke D.cleared16A.another B.other C.else D.more17A.for B.on C.at D.over18A.believes B.imagines C.requires D.hopes19A.pleasures B.challenges C.pities D.purposes20A.anybody B.nobody C.somebody D.everybody
下列关于实验的叙述正确的是
Usingtoomuchwaterorthrowingrubbishintoourriversareclearwaysthathumanscanputourwatersupplyinlessobviousways.Youmaywonderhowpaving铺砌aroadcanleadtolessusablefreshwater.Amajorpartofthewaterweuseeverydayisgroundwater.Groundwaterdoesnotcomefromlakesorrivers.Itcomesfromunderground.Themoreroadsandparkinglotswepavethelesswatercanflowintothegroundtobecomegroundwater. Humanactivityisnotresponsibleforallwatershortages短缺.Areasofdrierclimatesareofcoursemorelikelytohavedroughts干旱thanoneswithmorerainfallbutinanycasegoodmanagementcanhelptomakesurethereisenoughwatertomeetourbasicneeds. Thinkingaboutthewayweusewatereverydaycanmakeabigdifferencetoo.IntheUnitedStatesafamilyoffourcanuse1.5tonsofwateraday!Thisshowshowmuchwedependonwatertolivebutthere'salotwecandotolowerthenumber. Youcantakestepstosavewaterinyourhome.Tostartwithusethesameglassforyourdrinkingwaterallday.Washitonlyonceaday.Runyourdishwasheronlywhenitisfull.Helpyourparentsfixanyleaksinyourhome.Youcanevenhelptokeepourwatersupplycleanbyrecyclingbatteriesinsteadofthrowingthemaway. 1Whichofthefollowingismostlikelytoleadtolessgroundwater? A.Usingriverwater. B.Throwingbatteriesaway. C.Pavingparkinglots. D.Throwingrubbishintolakes. 2Whatcanbeinferredfromthetest? A.Allwatershortagesarebecauseofhumanbehavior. B.Ittakesalotofeffortstomeetourwaterneeds C.Thereismuchwecandotoreducefamilysize. D.TheaveragefamilyinAmericamakesproperuseofwater. 3Thelastparagraphisintendedto. A.showushowtofixleaksathome B.tellushowtorunadishwasher C.provewhatdrinkingglassisbestforus D.suggestwhatwedotosavewaterathome 4Thetextismainlyabout. A.whypavingroadsreducesourwater B.howmuchwedependonwatertolive C.whydroughtsoccurmoreindryclimates D.howhumanactivityaffectsourwatersupply
某小组利用草莓对影响光合作用的因素及果实发育期光合产物的转移进行了相关实验．图1表示在最适温度及其它条件保持不变的条件下草莓叶片CO2释放量随光照强度变化的曲线图2表示在适宜条件下向密闭温室中充入一定量14CO2后草莓叶片茎果实的放射性含量随时间变化的曲线．请回答下列问题 1图1中B点时叶肉细胞中产生的O2的扩散路径是．C点骤变为D点时短时间内三碳化合物的含量将．E点后曲线保持水平不变此时限制草莓光合作用速率的主要环境因素是． 2由图2可知t1～t2时间段叶片中有机物的含量下降．最可能的原因是．
高温胁迫是影响植物生长发育的重要因素之一高温会使番茄的生长发育受到限制．科学家将来自土壤细菌中的codA基因转入番茄使番茄对高温的耐受性大于野生型番茄．回答下列问题 1过程①获得的DNA片段填“可以”“部分可以”或“不可以”实现物种间的基因交流．采用PCR技术扩增codA基因时操作过程中需要加热至90～95℃的目的是． 2去磷酸化是去掉黏性末端最外侧游离的磷酸基团过程③对已开环的质粒两端去磷酸化的主要作用是为使codA基因在受体细胞中表达需要将其插在启动子之后目的是． 3过程④最常用的方法是过程⑤用到的细胞工程技术是．codA基因能否在番茄细胞中稳定遗传的关键是．
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