Practice1<br/>IfchiefexecutivesofleadingU.S.agri-biotechcompanieshavebeensufferingfromheartburnlately,itisn’tbecauseofanythingthey’vebeeneating.Rather,it’stheunsettlingknowledgethatlong-simmeringEuropeananxietiesovergeneticallymodified(g.m.)crops,likeocean-hoppingviruses,arespreadingacrosstheworld.<br/><alone></alone>UnlikeBritons,whoseconcernsaboutwhattheyeathavebeenontheriseeversince“madcowdisease”(eventhoughithadnothingtodowithgeneticengineering),Americanshaveseemedindifferenttog.m.foods.Iffoodmakerscannolongercountonthepublic’sunquestioningacceptanceoftheirproducts,it’snotjustbecauseofactivisttheatricsandshrillagitprop.Withbillionsofdollarsatrisk,thebiotechindustryhasbeguntofightback,formingcorporatealliancesandlaunchingamajorp.r.effortthatincludeslobbying,newresearcheffortstostillpublicfearsandTV,radioandnewspaperads.Sofar,theregulatorshaveapproveddozensofgeneticallymodifiedplantsforhumanconsumption.Butifpublicpressuregrows,itmaybeforcedtogoslowerinthefuture.Onepossibility:theFDAcouldbeginapplyingtog.m.foodsthepowersitalreadyhastoregulatefoodadditives.Byoverreactingtofearsfannedbywell-fedconsumersintheindustrializedworld,foodproducersmightuprootanindustrythatcouldsomedayprovidebillionsofpeopleintherestoftheworldwithcropstheydesperatelyneed.
Practice1<br/>IfchiefexecutivesofleadingU.S.agri-biotechcompanieshavebeensufferingfromheartburnlately,itisn’tbecauseofanythingthey’vebeeneating.Rather,it’stheunsettlingknowledgethatlong-simmeringEuropeananxietiesovergeneticallymodified(g.m.)crops,likeocean-hoppingviruses,arespreadingacrosstheworld.<br/><alone></alone>UnlikeBritons,whoseconcernsaboutwhattheyeathavebeenontheriseeversince“madcowdisease”(eventhoughithadnothingtodowithgeneticengineering),Americanshaveseemedindifferenttog.m.foods.Iffoodmakerscannolongercountonthepublic’sunquestioningacceptanceoftheirproducts,it’snotjustbecauseofactivisttheatricsandshrillagitprop.Withbillionsofdollarsatrisk,thebiotechindustryhasbeguntofightback,formingcorporatealliancesandlaunchingamajorp.r.effortthatincludeslobbying,newresearcheffortstostillpublicfearsandTV,radioandnewspaperads.Sofar,theregulatorshaveapproveddozensofgeneticallymodifiedplantsforhumanconsumption.Butifpublicpressuregrows,itmaybeforcedtogoslowerinthefuture.Onepossibility:theFDAcouldbeginapplyingtog.m.foodsthepowersitalreadyhastoregulatefoodadditives.Byoverreactingtofearsfannedbywell-fedconsumersintheindustrializedworld,foodproducersmightuprootanindustrythatcouldsomedayprovidebillionsofpeopleintherestoftheworldwithcropstheydesperatelyneed.
R是二元关系,且R=RºRºRºRº,那么下面哪一个不一定是传递的? A: R B: RºR C: RºRºR D: RºRºRºR
R是二元关系,且R=RºRºRºRº,那么下面哪一个不一定是传递的? A: R B: RºR C: RºRºR D: RºRºRºR
已知电阻R A: R=R=R B: R=R+R C: R=1/R+1/R D: R=1/R=1/R
已知电阻R A: R=R=R B: R=R+R C: R=1/R+1/R D: R=1/R=1/R
三个电阻的特性曲线如图所示,它们的阻值关系应为()。 A: R>R>R B: R>R>R C: R>R>R D: R=R=R
三个电阻的特性曲线如图所示,它们的阻值关系应为()。 A: R>R>R B: R>R>R C: R>R>R D: R=R=R
【单选题】电桥平衡条件是: A. R 1 R 3 = R 2 R 4 B. R 1 R 4 = R 2 R 3 C. R 1 R 2 = R 3 R 4 D. R 1> R 4 , R 2> R 3
【单选题】电桥平衡条件是: A. R 1 R 3 = R 2 R 4 B. R 1 R 4 = R 2 R 3 C. R 1 R 2 = R 3 R 4 D. R 1> R 4 , R 2> R 3
令R1={(a,b)∈R×R|a>b},R2={{(a,b)∈R×R|a≥b}},则R1∪R2 A: {{(a,b)∈R×R|a≥b}} B: {(a,b)∈R×R|a>b} C: {(a,b)∈R×R|a=b} D: {(a,b)∈R×R|a
令R1={(a,b)∈R×R|a>b},R2={{(a,b)∈R×R|a≥b}},则R1∪R2 A: {{(a,b)∈R×R|a≥b}} B: {(a,b)∈R×R|a>b} C: {(a,b)∈R×R|a=b} D: {(a,b)∈R×R|a
矩阵A,B,C满足AB=C,则这三个矩阵的秩满足关系( ) A: R(C)min{R(A),R(A)} B: R(C)<=min{R(A),R(A)} C: R(C)min{R(A),R(A)} D: R(C)>=min{R(A),R(A)}
矩阵A,B,C满足AB=C,则这三个矩阵的秩满足关系( ) A: R(C)min{R(A),R(A)} B: R(C)<=min{R(A),R(A)} C: R(C)min{R(A),R(A)} D: R(C)>=min{R(A),R(A)}
电阻率测井系列显示的低阻侵入,又叫减阻侵入,其特点为(),反之为增阻侵入。 A: R>R>R B: R<R<R C: R=R>R D: R≈R<R
电阻率测井系列显示的低阻侵入,又叫减阻侵入,其特点为(),反之为增阻侵入。 A: R>R>R B: R<R<R C: R=R>R D: R≈R<R
IA-32中指令“popl %ebp”的功能是( )。? R[ebp]←M[R[esp]],R[esp]←R[esp]+4|R[esp]←R[esp]-4,R[ebp]←M[R[esp]]|;R[ebp]←M[R[esp]],R[esp]←R[esp]-4|R[esp]←R[esp]+4,R[ebp]←M[R[esp]]
IA-32中指令“popl %ebp”的功能是( )。? R[ebp]←M[R[esp]],R[esp]←R[esp]+4|R[esp]←R[esp]-4,R[ebp]←M[R[esp]]|;R[ebp]←M[R[esp]],R[esp]←R[esp]-4|R[esp]←R[esp]+4,R[ebp]←M[R[esp]]
优级纯、分析纯、化学纯试剂的代号依次是() A: R\R\R B: R\R\P C: P\R\R D: R\P\R
优级纯、分析纯、化学纯试剂的代号依次是() A: R\R\R B: R\R\P C: P\R\R D: R\P\R