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在平行四边形ABCD中,E是BC边上一点,F是DE上一点,若∠B=∠AFE,AB=AF.求证: (1)△ADF≌△DEC. (2)BE=EF.
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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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阅读下列短文根据所给情节进行续写使之构成一个完整的故事. Desireea4﹣year﹣oldgirlwassobbingquietlyoverherfatherKenwhohaddiedninemonthsearlier.Shewashuggingaphotographofherfatherwithherfingersrunningaroundhisface.DaddyshesaidsoftlyWhywon'tyoucomeback? Insteadofgraduallyadjustingtoherfather'sdeathDesireerefusedtoacceptit.Daddywillbehomesoonshe'dtellhermother.He'satwork.Whensheplayedwithhertoytelephoneshepretendedshewaschattingwithherfather.ImissyouDaddyshe'dsayWhenwillyoucomeback?Desiree'ssituationmadehermotherworried. DayslateritwasKen'sbirthday.HowwillIsendhimacard?Desireeaskedhermother.Howaboutifwetiealettertoaballoonhermothersaidandsendituptoheaven?Desiree'seyesimmediatelylitup. HermothertookhertoastoreandDesireepickedoutaballoonwithHAPPYBIRTHDAYaboveadrawingofTheLittleMermaid美人鱼.Desireeandherfatherhadoftenwatchedit.Thechild'seyesshoneastheywereonthewaytoKen'sgrave.ThenDesireedictatedalettertoherdad.Tellhim‘HappybirthdayIloveyouandmissyou'sherattledoff快速说.‘IhopeyougetthisandcanwritetomeonmybirthdayinJanuary.' Hermotherwrotethemessageandtheiraddressonasmallpieceofpaperwhichwasthenwrappedinplasticandtiedtotheendofthestringontheballoon.FinallyDesireereleasedtheballoon.Foralmostanhourtheywatchedtheshiningspotofsilvergrowsmallerandsmallertilldisappear.NowDad'sgoingtowritebacktomeDesireedeclaredconfidently. Everydaysincethey'dreleasedtheballoonDesireehadaskedhermotherDoyouthinkDaddyhasmyballoonyet?Severalweekspassedandshestoppedasking. 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. Paragraph1 Oneday3000milesawayWadewasonaduckhuntwhensuddenlysomethinginthebushcaughthiseyes.﹣﹣﹣﹣ Paragraph2 Desiree'sfifthbirthdaycameandlaterontheafternoonapackagearrived.﹣﹣﹣﹣
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果蝇的红眼与白眼灰身与黑身长翅与残翅细眼与粗眼均是由一对等位基因控制的相对性状且这四对基因位于三对同源染色体上.将纯种黑身残翅白眼雌蝇与纯种灰身长翅红眼雄蝇交配F1中雌蝇全为灰身长翅红眼雄蝇全为灰身长翅白眼F1中雌雄个体相互交配F2中灰身长翅黑身残翅≈31.回答下列问题 1眼色中为显性性状控制细眼和粗眼的基因位于染色体上. 2灰身与黑身长翅与残翅这两对性状的遗传填“遵循”或“不遵循”基因的自由组合定律上述实验F2中会出现少量的灰身残翅和黑身长翅的个体推测其原因最可能是. 3科研人员偶然发现了一只无眼的雌果蝇研究结果表明控制有眼和无眼的基因不位于上述三对同源染色体上请设计实验判断无眼性状的显隐性..
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Theyearwas1956.MyfirsthusbandandIandournine﹣month﹣oldbabyPammovedfromSt.LouistoFortWorthTexas.Wefounda1loveapartmentandsettledinquickly.OnechillymorningI2headfortheLaundromat洗衣店.Iturned3theengineofour1953Chevy4warmupthecarandputPaminhercarseat5backthenwasinthefrontseat.Ilockedthecardoor.6Iputthebasketoflaundryinthebackseatandlockedtheotherdoor.7suddenIrealizedIhadlockedthe8keyandmybabyinthecarandlocked9Iout.Iimmediatelywentintopanicmode.Myneighborshadbothgonetoworkandtherewerenocellphonesbackthen.AsIlookedupthestreetIsawaredFordpickup10drivetowardme.Thedriverstoppedwhenhesawmecryingandwavingmyhands.Themanonthepassengersideofthetruckgotoutandsaid'Ihaveacarjustlikethisoneletmeseeifmykeywillopenthedoor.'Itdid!IhavetoldsomanypeoplethatGodwasthepassengerinaredFordpickupinOctober1956.
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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.
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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.
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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.
将一枚均匀的硬币投掷6次则正面出现的次数比反面出现的次数多的概率为.
下列关于实验的叙述正确的是
的展开式中的有理项共有.
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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