(2e^{-4t}-e^{-2t})的拉普拉斯变换为(frac{1}{(s+2)(s+4)})

图中所示为哪种情况下，(G_0(s)=dfrac{K(T_as+1)(T_bs+1)}{s^2(T_1s+1)})的Bode图

开环传递函数(G(s)=dfrac{2(s+1)}{s^2(s+a)}(a>0))的单位负反馈系统的根轨迹如图所示则使其稳定的的取值范围为（）

已知单位反馈系统的开环传递函数为(G_p(s)=frac{1.06}{s(s+1)(s+2)})要求设计串联校正装置，使校正后系统的静态速度误差系数为(K_v=5s^{-1})，并维持原系统的闭环主导极点不变。对于本例，适宜采用（）

图中系统的连续传递函数为(G(s)=dfrac{K}{(s+1)(s+2)},,,,,F(s)=1)则闭环系统的脉冲传递函数为

采样系统的闭环传递函数为(G_{rmCL}(z)=2z^{-1}-z^{-2})，则该系统的单位阶跃响应为

已知受控系统(sum(A,b,c^T))，系数矩阵为(A=left[begin{matrix}1&0&03&-1&10&2&0end{matrix}right],b=left[begin{matrix}211end{matrix}right]，c^T=left[begin{matrix}0&0&1end{matrix}right]),设计全维状态观测器(dot{hat{x}}=(A+Mc)hat{x}+bu-Mtilde{y})，则(M)取以下何值时，能使得观测器的极点为-3、-4和-5?

PartIIReadingComprehensionDirections:Thereareseveralpassagesinthissection.Eachpassageisfollowedbysomequestionsorunfinishedstatements.ForeachofthemtherearefourchoicesmarkedA),B),C)andD).Youshoulddecideonthebestchoice.PassageOneQuestions2to6arebasedonthefollowingpassage.“Chinaisexpectedtocompleteitsfirstexploration(探索)ofthemoonin2010andwillfoundamoonbasejustaswedidontheNorthandSouthPoles,”OuyangZiyuan,headofChina’smoonexplorationprogram,promisedduringnationalscienceandtechnologyweek.Afteritsfirstmaninspace,Chinaplansaspacelaboratory,alunarorbitertolookforvaluableelementsandminerals,robotlandingsonthemoonandthenthehumantouchdown.Thepriceofspaceexplorationisenormous.RussiaandtheUS,theonlytwocountriestohaveachievedmannedflight,arestrugglingtokeeptheirnewinvestment,theinternationalspacestation.ButChina,whichhasalongtraditioninphysics,mathematicsandengineering,findsitsdoctoralgraduateswelcomedintheUSandEuropefordecades.Andithasbeenabletolearnfrom40yearsofpioneeringsuccessesandmistakesbytheUSSRandtheUSA.Spaceflightisagambleandthestakes(赌注)arehigh.Ifsuccessful,Chinacouldbecomeamemberoftheworld’smostexclusiveclub,setupasecondhomeonthemoonandgetapowerfulhandatthestrategicbargainingtable.TwodesignersfromtheShenzhouIIIprojectsaidthat12astronautsnowareundergoingintensivetraining.Onemoreunmannedspaceflightisplannedbeforethefirstmannedlaunch.ExpertssaythattheShenzhouspacecraftalreadyprovidesChinawithaspacevehiclecapableofmounting(发起)alunarprogram.ChinesescientistshavealsopredictedthatMarswillbethenexttargetafterthemoon.2.AccordingtoOuyangZiyuan,________.

PartIIReadingComprehensionDirections:Thereareseveralpassagesinthissection.Eachpassageisfollowedbysomequestionsorunfinishedstatements.ForeachofthemtherearefourchoicesmarkedA),B),C)andD).Youshoulddecideonthebestchoice.PassageOneQuestions2to6arebasedonthefollowingpassage.“Chinaisexpectedtocompleteitsfirstexploration(探索)ofthemoonin2010andwillfoundamoonbasejustaswedidontheNorthandSouthPoles,”OuyangZiyuan,headofChina’smoonexplorationprogram,promisedduringnationalscienceandtechnologyweek.Afteritsfirstmaninspace,Chinaplansaspacelaboratory,alunarorbitertolookforvaluableelementsandminerals,robotlandingsonthemoonandthenthehumantouchdown.Thepriceofspaceexplorationisenormous.RussiaandtheUS,theonlytwocountriestohaveachievedmannedflight,arestrugglingtokeeptheirnewinvestment,theinternationalspacestation.ButChina,whichhasalongtraditioninphysics,mathematicsandengineering,findsitsdoctoralgraduateswelcomedintheUSandEuropefordecades.Andithasbeenabletolearnfrom40yearsofpioneeringsuccessesandmistakesbytheUSSRandtheUSA.Spaceflightisagambleandthestakes(赌注)arehigh.Ifsuccessful,Chinacouldbecomeamemberoftheworld’smostexclusiveclub,setupasecondhomeonthemoonandgetapowerfulhandatthestrategicbargainingtable.TwodesignersfromtheShenzhouIIIprojectsaidthat12astronautsnowareundergoingintensivetraining.Onemoreunmannedspaceflightisplannedbeforethefirstmannedlaunch.ExpertssaythattheShenzhouspacecraftalreadyprovidesChinawithaspacevehiclecapableofmounting(发起)alunarprogram.ChinesescientistshavealsopredictedthatMarswillbethenexttargetafterthemoon.2.AccordingtoOuyangZiyuan,________.

现在的100元和5年以后的248元两笔资金在第2年年末价值相等，若利率不变，则这两笔资金在第3年末的价值

2.Theboyapicturenow.

Perhapsyouhavebeentoldaboutsomehabitswhichkeepapersonfromreadingfastandhavebeenstronglyaskedtobreakthosehabitswhichyoumighthave.Doyoustillhaveanyofthesebadhabits?Checkyourselfbyanswering“yes”or“no”tothesequestions:1.Doyoumoveyourlipswhenreadingsilently?2.Doyoupointtowordswithyourfingerasyouread?3.Doyoumoveyourheadfromsidetosideasyouread?Ifyouanswer“yes”toanyofthesequestions,startatoncetobreakthehabit.Ifyoumoveyourlips,holdyourfingersoverthem,orholdapieceofpaperbetweenyourlipswhileyouarereading.Thenifyoupointtowords,holdthetwosidesofyourbook,onesidewithyourlefthand,theothersidewithyourrighthand.Thenyouwillnothaveafreefingertouseinpointingwhilereading.Ifyoumoveyourhead,placeyourchininonehand,andholdyourheadstill.Ifyoureadnomorethanoneortwoorthreewordsatatime,youneedtoworkveryhardinlearningtotakeinmorewordsateachglanceasyoureyestravelacrossthelinesofwords.46.You______thosehabitsthatwearetalkingaboutinthispassage.

TheissuingdateofadraftisMay31.Iftenorofthedraftisstatingas（1）“at90daysafterdate”，（2）“atonemonthafterdate”,thedateofpaymentwillbe（）

我国航空法律不同于航空规章的重要特征是：

人生价值评价的根本尺度，是看一个人的人生活动（），是否促进了历史的进步。