填空题已知f(x)=，则f(n)(3)=________．

填空题由曲线y=lnx与两直线y=e+1-x及y=0围成平面图形的面积S=______.

填空题=________．

填空题当x→0时，－1～cos2x－1，则a=________．

填空题=________.

填空题=________

填空题=________．

填空题设A是3阶矩阵，ξ 1 ，ξ 2 ，ξ 3 是三个线性无关的3维列向量，满足Aξ i =ξ i ，i=1，2，3，则A=________．

填空题设

填空题若二次型f(x 1 ，x 2 ，x 3 )一2x 1 2 +x 2 2 +x 2 3 +2x 1 x 2 +tx 2 x 3 是正定的，则t的取值范围是________。

填空题Allmodernhumanoriginatedinsub-SaharanAfrica,accordingtoanewstudyboastedbyitsfoundersasthe"finalblow"againstanopposingviewpoint.Notsofast,saysoneanthropologistwhofindsflawsintheevidence.Thenewstudy,publishedintheJuly19issueofthejournalNature,deliverswhattheresearcherssaycouldbethefinalverdictinsupportofthesinglepoint"OutofAfrica"theory.Manicaandcolleaguestookmultiplemeasurementsofmorethan4,500malefossilskullsfrom105populationsaroundtheglobe.Theycombinedtheresultswithdatafromstudiesofglobalgeneticvariationsinhumans,findingthatbothgeneticandskullvariabilitydecreasedwithdistancefromAfrica.SopopulationsinsoutheasternAfricaheldthehighestvariabilitycomparedwithpopulationsinothercountries.Theresultsheldevenwhenthescientistsaccountedforclimate,sinceclimateconditionscanleadtochangesinskullfeatures."Inverycoldclimatesyoutendtogenerateaslightlythickerbrowridge.Whetherornotthat'stokeephorribleblizzardsoutofyoureyes,Idon'tknow,"Amossaid.Paststudiesbasedonskullmorphologyhavebeenweakandhavesupportedbothofthehumanoriginviews.Inhisownresearch,Hawksisfundingthatnaturalselectionhasledtochangesinthousandsofgenesduringonlythepastfewthousandyears."I'mreallythinkingjusttheoppositeofthispaper,"Hawkssaid."Therearedifferencesintheskullbetweenpopulations,includingtheirvariability,butitismostlyduetoveryrecenteffectsandnottheoriginofmodernhumans.""ThemuhiregionalideaisidenticaltotherecentAfricanoriginidea,exceptforitspredictionthatEuropeansandAsianswerepartofthesinglepopulationoforiginanddidn'tbecomeextinct."[A]"HumansseemtohavepouredoutofAfrica,spreadoutacrosstheworld,butatareallyquiteuniformratesuchthatyougetthislovelygraduallossofdiversity,"saidstudyteammemberWilliamAmosoftheUniversityofCambridge.[B]Allmodernhumansoriginatedfromthesameancestorsandtheykeptevolvingasthesocietyadvances.Somespeciesdiedoutbutothersremainedtoliveontheearth,whichisstillimpossibletosolve.[C]Attheendoftheday,aresolutiontothe"OutofAfrica"debatemaybeimpossible,hesaid.Mostoftheevidencecanbeinterpretedassupportingbothhuman-originstheories."It'sreallyhardtofindthetwo,"Hawkssaid.[D]Thisstudy"addsastronglineofevidencetotheOutofAfrica(hypothesis)usingsuchmorphology,"saidpaleontologistWillHarcourt-SmithoftheAmericanMuseumofNaturalHistoryinNewYork.Harcourt-Smithwasnotinvolvedinthecurrentresearch.[E]Debateovertheoriginsofmodernhumanshassimmeredamonganthropologistsforyears,withonetheoryassertingthatHomosapiensmigratedacrosstheworldfromasinglepointinAfrica.TheothertheorystatesthatmultiplepopulationsofHomosapiensindependentlyevolvedfromHomoerectusinregionsbeyondAfrica.[F]TherecentstudywasfundedbytheBiotechnologyandBiologicalSciencesResearchCouncil.Ithasprovidedconclusiveevidenceconcerningtheactualprocessofhumanevolution.[G]"Wehavecombinedourgeneticdatawithnewmeasurementsofalargesampleofskullstoshowdefinitelythatmodernhumansoriginatedfromasingleareainsub-SaharanAfrica,"saidleadresearcherAndreaManicaoftheUniversityofCambridge.41.______42.______43.______44.______45.______