2023年4月自考00600高級(jí)英語試題及答案

高級(jí)英語年月真題

0060020234

1、【單選題】I()thedecisionofmylocalcounciltoinstallcamerasaroundthe

center.

arbitrate

appraise

A:

applaud

B:

audit

C:

答D:案：C

2、【單選題】Shehasalreadyhadto()threepainfuloperationsonherleg.

endure

present

A:

attend

B:

suppress

C:

答D:案：A

3、【單選題】Infact,theCovid-19pandemichasexposedamajor()inthis

incompleteurbanization.

leakage

backlash

A:

shortage

B:

drawback

C:

答D:案：D

4、【單選題】()additivessuchascolorings,sweetenersandflavorenhancers

aren'tpermittedinbabyfoods.

Pretentious

Counterfeit

A:

Artificial

B:

Spurious

C:

答D:案：C

5、【單選題】Thegrowthofapopulationresultsfromthe()ofbirthsover

deathsaswellasthemovementofpeoplebetweenregionsorcountries.

excess

access

A:

process

B:

success

C:

答D:案：A

6、【單選題】Theamountofalcoholhehaddrunkseriously()hisabilityto

drive.

injured

impaired

A:

abused

B:

spoiled

C:

答D:案：B

7、【單選題】Howto()thebottlenecksoftechnologicaldevelopmentinkeyareas

hasbecomeamajortestfortherealizationofsmoothdomesticcirculation.

breakwith

breakup

A:

breakdown

B:

breakthrough

C:

答D:案：D

8、【單選題】Wehavestudentsupportadvisers,andwheneverweneedhelpwith()

tasksoracademictasks,wecanjustreachthematanytime.

mutational

mundane

A:

municipal

B:

mutual

C:

答D:案：B

9、【單選題】Sheclaimedthattheriseinunemploymentwasjustafurther()of

thegovernment'sincompetence.

phenomenon

manifestation

A:

appearance

B:

signature

C:

D:

答案：B

10、【單選題】Somedisheswouldbeveryblandwithoutthe()useofspicesand

otherseasonings.

judicial

legal

A:

judicious

B:

legislative

C:

答D:案：C

11、【單選題】Thecompany()customersbysellingoldcomputersasnewones.

consoled

deceived

A:

confounded

B:

perceived

C:

答D:案：B

12、【單選題】Themodernizationofagricultureis()aboutfarmingonly,but

moreimportantlyaboutimprovingthewell-beingofruralresidents.

bynomeans

innotime

A:

byanymeans

B:

atanytime

C:

答D:案：A

13、【單選題】Cold-chainserviceswillbecheckedthoroughlytominimizevirus()

risks.

transportation

transaction

A:

transmission

B:

transition

C:

答D:案：C

14、【單選題】Powellhurthisbackwhenhefelloffthehorseandwas()fora

year.

laidup

A:

laidout

laidon

B:

laiddown

C:

答D:案：A

15、【單選題】Hisjealouscompetitorsoftenaccusehimofbeingtoo()andof

takingawaytheirbusiness.

acknowledged

acquiescent

A:

accustomed

B:

acquisitive

C:

答D:案：D

16、【單選題】(1)OnOctober24th,2003Concordemadeitslastcommercialflight.

Itcarriedafullloadofpassengers,100ofthem,fromNewYorktoLondon.Andit

didsointhreeandahalfhours.Itwasabletomakethejourneysorapidlybecause

itstopspeedwasMach2.04-justovertwicethevelocityofsound.(2)Initsday,

Concordewasasuperbpieceofengineering.Butitwasalsoavanityproject,

**cookedup**intheearly1960sbytheBritishandFrenchgovernments.Issues

likeprofitwereignored.Howeversuperbtheengineering,withthetechnologythen

availabletheprofitableoperationofsuchaplanewasimpossible.(3)

_Technologymoveson,though,andseveraltrulycommercialundertakingsthinkthe

timeisnowripeforsomethingsimilar._Mostoftherunningisbeingmadeby

threeAmericanfirms,Aerion,BoomandSpike.Aerion'soffering,theAS2,isa12-

seaterintendedtoflyatMach1.4.Overture,theaircraftplannedbyBoom,will

gettoMach2.2.Itwillcarry55-75passengers.Spike'sproposal,theS-512,lies

betweentheseextremes.Itisintendedtocarry18passengersatMach1.6.All

threefirmsthinkthatimprovementsinmaterials,enginedesignandthe

understandingofaerodynamicsmeantheirproposedcraftcanbeoperatedprofitably

andwithouttoomuchdiscomfort,intheformofsonicbooms,tothoseontheground

below.(4)InFebruaryAerionsignedadevelopmentdealwithBoeing.Italsohas

anarrangementwithGeneralElectric(GE)todevelopasupersonicengine

calledAffinity,capableofoperatingefficientlybothsubsonically

andsupersonically.Theplanistoattachthese,threeatatime,toan

airframebuiltbySpiritAeroSystems,alargemanufacturerofairframecomponents.

Andallthiswillcometopass,Aerionclaims,by2023-thecurrenttargetfor

theAS2totakeoff.(5)BoomhasyettoannounceapropulsionsystemforOverture.

Butit,too,hasdevelopmentmoney,havingreceivedatrancheofminventure

fundingin2017andafurthermthisJanuary.Anditwillsoonhaveaprototype,a

one-third-scaleaircraftthatitcallsBabyBoom.Thisispoweredbythreeof

GE'sJ85-15engines-themilitaryversionsoftheCJ610,anestablishedworkhorse

ofbusinessjets.Allbeingwell,BabyBoomwilltaketotheairearlynext

yearandflyatMach2.2.(6)LikeBoom,Spikehasyettopickanengine,though

itplanstodosobytheendoftheyear.Italsoplansasubsonicdemonstration

flightinJune,andasupersonicdemonstrationnextyear._Whethersupersonic

commercialaviationreallywillworkthistimeshouldthusbeclearbythemid

2020s._Afew**visionaries**are,however,lookingbeyondthemerelysupersonic.

Theywanttogohypersonic(高超音速)-beyondMach5.Thatwouldmakeitpossible

toflytoanairport'santipodesinlessthanfourhours.(7)Atthisspeedthe

physicsgetscary.Airenteringahypersonicjetenginewouldbetravellingat

morethan1.7kmpersecond.Slowingthisairdownsufficientlyforittobe

manageablewouldconvertitskineticenergy(動(dòng)能)intoheatsointensethatit

wouldmeltmostofthematerialsofwhichsuchanenginemightbemade.(8)_All

thisexplainswhyexistinghypersonicvehicles-namelysatellite-launchers-are

rocket-propelled._Arocketcarriesitsownoxidantandsodoesnotneedto

breatheair.Theonlyalternativethathasbeentestedexperimentallyiscalleda

supersonic-combustionramjet.Thisdoesnotrequiretheincomingairtobeslowed

downtothesameextentasaturbofan.ButithastobeacceleratedtoMach5to

startoperating,usuallybyarocket.(9)AsmallBritishcompanycalled

ReactionEnginesdoes,however,haveanalternativeonoffer._Skylon,asReaction

Enginesnamesitsdesign,wouldbepoweredbyenginesabletoswitchbetweenair

andliquidoxygen._TheyareknownasSynergeticAirBreathingRocketEngines

(SABRE)andwouldbefuelledbyliquidhydrogen,whichhasatemperatureofless

than20degreesaboveabsolutezero.Thetrick,whenaSABREisinair-breathing

mode,wouldbetousethiscoldnesstoabsorbheatgeneratedbytheinrushingair

beforeitcouldcausedamage.Aheat-exchangerintendedtodothiswas

testedsuccessfullyinApril.(10)Atbest,thechancesofatinyteamworkingin

themetaphoricalequivalentofagardenshedcrackingtheproblemofair-breathing

hypersonicflightareslim.Butperhapstheyarenotzero.Thefundamentaldesign

lookssound,andtherehas,overtheyears,beenenoughinterestfromoutsiders

suchasBoeing,Rolls-RoyceandBAEtokeepthedreamalive.(11)_IfSkylondoes

eventuallyfly,itsfirstuseislikelytobeasanunmannedspaceplanecarrying

objectsintoorbit._Butoneday,perhaps,itorasuccessorwill-forthoserich

enough-makepoppingovertoSydneyforaweekendbreakseemjustthething.

WhatcanbelearnedaboutConcordfromParagraph1?

Itsfullloadwas100passengers.

Ittraveledatthevelocityofsound.

A:

Itscommercialservicebeganin2003.

B:

ItflewfromLondontoNewYorkin3hours.

C:

D:

答案：A

17、【單選題】(1)OnOctober24th,2003Concordemadeitslastcommercialflight.

Itcarriedafullloadofpassengers,100ofthem,fromNewYorktoLondon.Andit

didsointhreeandahalfhours.Itwasabletomakethejourneysorapidlybecause

itstopspeedwasMach2.04-justovertwicethevelocityofsound.(2)Initsday,

Concordewasasuperbpieceofengineering.Butitwasalsoavanityproject,

**cookedup**intheearly1960sbytheBritishandFrenchgovernments.Issues

likeprofitwereignored.Howeversuperbtheengineering,withthetechnologythen

availabletheprofitableoperationofsuchaplanewasimpossible.(3)

_Technologymoveson,though,andseveraltrulycommercialundertakingsthinkthe

timeisnowripeforsomethingsimilar._Mostoftherunningisbeingmadeby

threeAmericanfirms,Aerion,BoomandSpike.Aerion'soffering,theAS2,isa12-

seaterintendedtoflyatMach1.4.Overture,theaircraftplannedbyBoom,will

gettoMach2.2.Itwillcarry55-75passengers.Spike'sproposal,theS-512,lies

betweentheseextremes.Itisintendedtocarry18passengersatMach1.6.All

threefirmsthinkthatimprovementsinmaterials,enginedesignandthe

understandingofaerodynamicsmeantheirproposedcraftcanbeoperatedprofitably

andwithouttoomuchdiscomfort,intheformofsonicbooms,tothoseontheground

below.(4)InFebruaryAerionsignedadevelopmentdealwithBoeing.Italsohas

anarrangementwithGeneralElectric(GE)todevelopasupersonicengine

calledAffinity,capableofoperatingefficientlybothsubsonically

andsupersonically.Theplanistoattachthese,threeatatime,toan

airframebuiltbySpiritAeroSystems,alargemanufacturerofairframecomponents.

Andallthiswillcometopass,Aerionclaims,by2023-thecurrenttargetfor

theAS2totakeoff.(5)BoomhasyettoannounceapropulsionsystemforOverture.

Butit,too,hasdevelopmentmoney,havingreceivedatrancheofminventure

fundingin2017andafurthermthisJanuary.Anditwillsoonhaveaprototype,a

one-third-scaleaircraftthatitcallsBabyBoom.Thisispoweredbythreeof

GE'sJ85-15engines-themilitaryversionsoftheCJ610,anestablishedworkhorse

ofbusinessjets.Allbeingwell,BabyBoomwilltaketotheairearlynext

yearandflyatMach2.2.(6)LikeBoom,Spikehasyettopickanengine,though

itplanstodosobytheendoftheyear.Italsoplansasubsonicdemonstration

flightinJune,andasupersonicdemonstrationnextyear._Whethersupersonic

commercialaviationreallywillworkthistimeshouldthusbeclearbythemid

2020s._Afew**visionaries**are,however,lookingbeyondthemerelysupersonic.

Theywanttogohypersonic(高超音速)-beyondMach5.Thatwouldmakeitpossible

toflytoanairport'santipodesinlessthanfourhours.(7)Atthisspeedthe

physicsgetscary.Airenteringahypersonicjetenginewouldbetravellingat

morethan1.7kmpersecond.Slowingthisairdownsufficientlyforittobe

manageablewouldconvertitskineticenergy(動(dòng)能)intoheatsointensethatit

wouldmeltmostofthematerialsofwhichsuchanenginemightbemade.(8)_All

thisexplainswhyexistinghypersonicvehicles-namelysatellite-launchers-are

rocket-propelled._Arocketcarriesitsownoxidantandsodoesnotneedto

breatheair.Theonlyalternativethathasbeentestedexperimentallyiscalleda

supersonic-combustionramjet.Thisdoesnotrequiretheincomingairtobeslowed

downtothesameextentasaturbofan.ButithastobeacceleratedtoMach5to

startoperating,usuallybyarocket.(9)AsmallBritishcompanycalled

ReactionEnginesdoes,however,haveanalternativeonoffer._Skylon,asReaction

Enginesnamesitsdesign,wouldbepoweredbyenginesabletoswitchbetweenair

andliquidoxygen._TheyareknownasSynergeticAirBreathingRocketEngines

(SABRE)andwouldbefuelledbyliquidhydrogen,whichhasatemperatureofless

than20degreesaboveabsolutezero.Thetrick,whenaSABREisinair-breathing

mode,wouldbetousethiscoldnesstoabsorbheatgeneratedbytheinrushingair

beforeitcouldcausedamage.Aheat-exchangerintendedtodothiswas

testedsuccessfullyinApril.(10)Atbest,thechancesofatinyteamworkingin

themetaphoricalequivalentofagardenshedcrackingtheproblemofair-breathing

hypersonicflightareslim.Butperhapstheyarenotzero.Thefundamentaldesign

lookssound,andtherehas,overtheyears,beenenoughinterestfromoutsiders

suchasBoeing,Rolls-RoyceandBAEtokeepthedreamalive.(11)_IfSkylondoes

eventuallyfly,itsfirstuseislikelytobeasanunmannedspaceplanecarrying

objectsintoorbit._Butoneday,perhaps,itorasuccessorwill-forthoserich

enough-makepoppingovertoSydneyforaweekendbreakseemjustthething.In

Paragraph2,“cookedup”isclosestinmeaningto().

heldon

givenup

A:

carriedon

B:

drawnup

C:

答D:案：D

18、【單選題】(1)OnOctober24th,2003Concordemadeitslastcommercialflight.

Itcarriedafullloadofpassengers,100ofthem,fromNewYorktoLondon.Andit

didsointhreeandahalfhours.Itwasabletomakethejourneysorapidlybecause

itstopspeedwasMach2.04-justovertwicethevelocityofsound.(2)Initsday,

Concordewasasuperbpieceofengineering.Butitwasalsoavanityproject,

**cookedup**intheearly1960sbytheBritishandFrenchgovernments.Issues

likeprofitwereignored.Howeversuperbtheengineering,withthetechnologythen

availabletheprofitableoperationofsuchaplanewasimpossible.(3)

_Technologymoveson,though,andseveraltrulycommercialundertakingsthinkthe

timeisnowripeforsomethingsimilar._Mostoftherunningisbeingmadeby

threeAmericanfirms,Aerion,BoomandSpike.Aerion'soffering,theAS2,isa12-

seaterintendedtoflyatMach1.4.Overture,theaircraftplannedbyBoom,will

gettoMach2.2.Itwillcarry55-75passengers.Spike'sproposal,theS-512,lies

betweentheseextremes.Itisintendedtocarry18passengersatMach1.6.All

threefirmsthinkthatimprovementsinmaterials,enginedesignandthe

understandingofaerodynamicsmeantheirproposedcraftcanbeoperatedprofitably

andwithouttoomuchdiscomfort,intheformofsonicbooms,tothoseontheground

below.(4)InFebruaryAerionsignedadevelopmentdealwithBoeing.Italsohas

anarrangementwithGeneralElectric(GE)todevelopasupersonicengine

calledAffinity,capableofoperatingefficientlybothsubsonically

andsupersonically.Theplanistoattachthese,threeatatime,toan

airframebuiltbySpiritAeroSystems,alargemanufacturerofairframecomponents.

Andallthiswillcometopass,Aerionclaims,by2023-thecurrenttargetfor

theAS2totakeoff.(5)BoomhasyettoannounceapropulsionsystemforOverture.

Butit,too,hasdevelopmentmoney,havingreceivedatrancheofminventure

fundingin2017andafurthermthisJanuary.Anditwillsoonhaveaprototype,a

one-third-scaleaircraftthatitcallsBabyBoom.Thisispoweredbythreeof

GE'sJ85-15engines-themilitaryversionsoftheCJ610,anestablishedworkhorse

ofbusinessjets.Allbeingwell,BabyBoomwilltaketotheairearlynext

yearandflyatMach2.2.(6)LikeBoom,Spikehasyettopickanengine,though

itplanstodosobytheendoftheyear.Italsoplansasubsonicdemonstration

flightinJune,andasupersonicdemonstrationnextyear._Whethersupersonic

commercialaviationreallywillworkthistimeshouldthusbeclearbythemid

2020s._Afew**visionaries**are,however,lookingbeyondthemerelysupersonic.

Theywanttogohypersonic(高超音速)-beyondMach5.Thatwouldmakeitpossible

toflytoanairport'santipodesinlessthanfourhours.(7)Atthisspeedthe

physicsgetscary.Airenteringahypersonicjetenginewouldbetravellingat

morethan1.7kmpersecond.Slowingthisairdownsufficientlyforittobe

manageablewouldconvertitskineticenergy(動(dòng)能)intoheatsointensethatit

wouldmeltmostofthematerialsofwhichsuchanenginemightbemade.(8)_All

thisexplainswhyexistinghypersonicvehicles-namelysatellite-launchers-are

rocket-propelled._Arocketcarriesitsownoxidantandsodoesnotneedto

breatheair.Theonlyalternativethathasbeentestedexperimentallyiscalleda

supersonic-combustionramjet.Thisdoesnotrequiretheincomingairtobeslowed

downtothesameextentasaturbofan.ButithastobeacceleratedtoMach5to

startoperating,usuallybyarocket.(9)AsmallBritishcompanycalled

ReactionEnginesdoes,however,haveanalternativeonoffer._Skylon,asReaction

Enginesnamesitsdesign,wouldbepoweredbyenginesabletoswitchbetweenair

andliquidoxygen._TheyareknownasSynergeticAirBreathingRocketEngines

(SABRE)andwouldbefuelledbyliquidhydrogen,whichhasatemperatureofless

than20degreesaboveabsolutezero.Thetrick,whenaSABREisinair-breathing

mode,wouldbetousethiscoldnesstoabsorbheatgeneratedbytheinrushingair

beforeitcouldcausedamage.Aheat-exchangerintendedtodothiswas

testedsuccessfullyinApril.(10)Atbest,thechancesofatinyteamworkingin

themetaphoricalequivalentofagardenshedcrackingtheproblemofair-breathing

hypersonicflightareslim.Butperhapstheyarenotzero.Thefundamentaldesign

lookssound,andtherehas,overtheyears,beenenoughinterestfromoutsiders

suchasBoeing,Rolls-RoyceandBAEtokeepthedreamalive.(11)_IfSkylondoes

eventuallyfly,itsfirstuseislikelytobeasanunmannedspaceplanecarrying

objectsintoorbit._Butoneday,perhaps,itorasuccessorwill-forthoserich

enough-makepoppingovertoSydneyforaweekendbreakseemjustthething.

AccordingtoParagraph3,whichofthefollowingstatementsistrue?

Thetechnologyofsupersonicairlinersismature.

AS2'scapacityisthelargestamongthethreetypes.

A:

TheaircraftplannedbyBoomisthefastestofthethreetypes.

B:

ThecommercialoperationsaremadebyoneAmericanfirm.

C:

答D:案：C

19、【單選題】(1)OnOctober24th,2003Concordemadeitslastcommercialflight.

Itcarriedafullloadofpassengers,100ofthem,fromNewYorktoLondon.Andit

didsointhreeandahalfhours.Itwasabletomakethejourneysorapidlybecause

itstopspeedwasMach2.04-justovertwicethevelocityofsound.(2)Initsday,

Concordewasasuperbpieceofengineering.Butitwasalsoavanityproject,

**cookedup**intheearly1960sbytheBritishandFrenchgovernments.Issues

likeprofitwereignored.Howeversuperbtheengineering,withthetechnologythen

availabletheprofitableoperationofsuchaplanewasimpossible.(3)

_Technologymoveson,though,andseveraltrulycommercialundertakingsthinkthe

timeisnowripeforsomethingsimilar._Mostoftherunningisbeingmadeby

threeAmericanfirms,Aerion,BoomandSpike.Aerion'soffering,theAS2,isa12-

seaterintendedtoflyatMach1.4.Overture,theaircraftplannedbyBoom,will

gettoMach2.2.Itwillcarry55-75passengers.Spike'sproposal,theS-512,lies

betweentheseextremes.Itisintendedtocarry18passengersatMach1.6.All

threefirmsthinkthatimprovementsinmaterials,enginedesignandthe

understandingofaerodynamicsmeantheirproposedcraftcanbeoperatedprofitably

andwithouttoomuchdiscomfort,intheformofsonicbooms,tothoseontheground

below.(4)InFebruaryAerionsignedadevelopmentdealwithBoeing.Italsohas

anarrangementwithGeneralElectric(GE)todevelopasupersonicengine

calledAffinity,capableofoperatingefficientlybothsubsonically

andsupersonically.Theplanistoattachthese,threeatatime,toan

airframebuiltbySpiritAeroSystems,alargemanufacturerofairframecomponents.

Andallthiswillcometopass,Aerionclaims,by2023-thecurrenttargetfor

theAS2totakeoff.(5)BoomhasyettoannounceapropulsionsystemforOverture.

Butit,too,hasdevelopmentmoney,havingreceivedatrancheofminventure

fundingin2017andafurthermthisJanuary.Anditwillsoonhaveaprototype,a

one-third-scaleaircraftthatitcallsBabyBoom.Thisispoweredbythreeof

GE'sJ85-15engines-themilitaryversionsoftheCJ610,anestablishedworkhorse

ofbusinessjets.Allbeingwell,BabyBoomwilltaketotheairearlynext

yearandflyatMach2.2.(6)LikeBoom,Spikehasyettopickanengine,though

itplanstodosobytheendoftheyear.Italsoplansasubsonicdemonstration

flightinJune,andasupersonicdemonstrationnextyear._Whethersupersonic

commercialaviationreallywillworkthistimeshouldthusbeclearbythemid

2020s._Afew**visionaries**are,however,lookingbeyondthemerelysupersonic.

Theywanttogohypersonic(高超音速)-beyondMach5.Thatwouldmakeitpossible

toflytoanairport'santipodesinlessthanfourhours.(7)Atthisspeedthe

physicsgetscary.Airenteringahypersonicjetenginewouldbetravellingat

morethan1.7kmpersecond.Slowingthisairdownsufficientlyforittobe

manageablewouldconvertitskineticenergy(動(dòng)能)intoheatsointensethatit

wouldmeltmostofthematerialsofwhichsuchanenginemightbemade.(8)_All

thisexplainswhyexistinghypersonicvehicles-namelysatellite-launchers-are

rocket-propelled._Arocketcarriesitsownoxidantandsodoesnotneedto

breatheair.Theonlyalternativethathasbeentestedexperimentallyiscalleda

supersonic-combustionramjet.Thisdoesnotrequiretheincomingairtobeslowed

downtothesameextentasaturbofan.ButithastobeacceleratedtoMach5to

startoperating,usuallybyarocket.(9)AsmallBritishcompanycalled

ReactionEnginesdoes,however,haveanalternativeonoffer._Skylon,asReaction

Enginesnamesitsdesign,wouldbepoweredbyenginesabletoswitchbetweenair

andliquidoxygen._TheyareknownasSynergeticAirBreathingRocketEngines

(SABRE)andwouldbefuelledbyliquidhydrogen,whichhasatemperatureofless

than20degreesaboveabsolutezero.Thetrick,whenaSABREisinair-breathing

mode,wouldbetousethiscoldnesstoabsorbheatgeneratedbytheinrushingair

beforeitcouldcausedamage.Aheat-exchangerintendedtodothiswas

testedsuccessfullyinApril.(10)Atbest,thechancesofatinyteamworkingin

themetaphoricalequivalentofagardenshedcrackingtheproblemofair-breathing

hypersonicflightareslim.Butperhapstheyarenotzero.Thefundamentaldesign

lookssound,andtherehas,overtheyears,beenenoughinterestfromoutsiders

suchasBoeing,Rolls-RoyceandBAEtokeepthedreamalive.(11)_IfSkylondoes

eventuallyfly,itsfirstuseislikelytobeasanunmannedspaceplanecarrying

objectsintoorbit._Butoneday,perhaps,itorasuccessorwill-forthoserich

enough-makepoppingovertoSydneyforaweekendbreakseemjustthething.

AccordingtoParagraph4,AS2().

willnotbeabletorunsubsonically

willnotbemanufactureduntil2023

A:

willusetheairframebuiltbyAerion

B:

C:

willbeequippedwithsupersonicengines

答D:案：D

20、【單選題】(1)OnOctober24th,2003Concordemadeitslastcommercialflight.

Itcarriedafullloadofpassengers,100ofthem,fromNewYorktoLondon.Andit

didsointhreeandahalfhours.Itwasabletomakethejourneysorapidlybecause

itstopspeedwasMach2.04-justovertwicethevelocityofsound.(2)Initsday,

Concordewasasuperbpieceofengineering.Butitwasalsoavanityproject,

**cookedup**intheearly1960sbytheBritishandFrenchgovernments.Issues

likeprofitwereignored.Howeversuperbtheengineering,withthetechnologythen

availabletheprofitableoperationofsuchaplanewasimpossible.(3)

_Technologymoveson,though,andseveraltrulycommercialundertakingsthinkthe

timeisnowripeforsomethingsimilar._Mostoftherunningisbeingmadeby

threeAmericanfirms,Aerion,BoomandSpike.Aerion'soffering,theAS2,isa12-

seaterintendedtoflyatMach1.4.Overture,theaircraftplannedbyBoom,will

gettoMach2.2.Itwillcarry55-75passengers.Spike'sproposal,theS-512,lies

betweentheseextremes.Itisintendedtocarry18passengersatMach1.6.All

threefirmsthinkthatimprovementsinmaterials,enginedesignandthe

understandingofaerodynamicsmeantheirproposedcraftcanbeoperatedprofitably

andwithouttoomuchdiscomfort,intheformofsonicbooms,tothoseontheground

below.(4)InFebruaryAerionsignedadevelopmentdealwithBoeing.Italsohas

anarrangementwithGeneralElectric(GE)todevelopasupersonicengine

calledAffinity,capableofoperatingefficientlybothsubsonically

andsupersonically.Theplanistoattachthese,threeatatime,toan

airframebuiltbySpiritAeroSystems,alargemanufacturerofairframecomponents.

Andallthiswillcometopass,Aerionclaims,by2023-thecurrenttargetfor

theAS2totakeoff.(5)BoomhasyettoannounceapropulsionsystemforOverture.

Butit,too,hasdevelopmentmoney,havingreceivedatrancheofminventure

fundingin2017andafurthermthisJanuary.Anditwillsoonhaveaprototype,a

one-third-scaleaircraftthatitcallsBabyBoom.Thisispoweredbythreeof

GE'sJ85-15engines-themilitaryversionsoftheCJ610,anestablishedworkhorse

ofbusinessjets.Allbeingwell,BabyBoomwilltaketotheairearlynext

yearandflyatMach2.2.(6)LikeBoom,Spikehasyettopickanengine,though

itplanstodosobytheendoftheyear.Italsoplansasubsonicdemonstration

flightinJune,andasupersonicdemonstrationnextyear._Whethersupersonic

commercialaviationreallywillworkthistimeshouldthusbeclearbythemid

2020s._Afew**visionaries**are,however,lookingbeyondthemerelysupersonic.

Theywanttogohypersonic(高超音速)-beyondMach5.Thatwouldmakeitpossible

toflytoanairport'santipodesinlessthanfourhours.(7)Atthisspeedthe

physicsgetscary.Airenteringahypersonicjetenginewouldbetravellingat

morethan1.7kmpersecond.Slowingthisairdownsufficientlyforittobe

manageablewouldconvertitskineticenergy(動(dòng)能)intoheatsointensethatit

wouldmeltmostofthematerialsofwhichsuchanenginemightbemade.(8)_All

thisexplainswhyexistinghypersonicvehicles-namelysatellite-launchers-are

rocket-propelled._Arocketcarriesitsownoxidantandsodoesnotneedto

breatheair.Theonlyalternativethathasbeentestedexperimentallyiscalleda

supersonic-combustionramjet.Thisdoesnotrequiretheincomingairtobeslowed

downtothesameextentasaturbofan.ButithastobeacceleratedtoMach5to

startoperating,usuallybyarocket.(9)AsmallBritishcompanycalled

ReactionEnginesdoes,however,haveanalternativeonoffer._Skylon,asReaction

Enginesnamesitsdesign,wouldbepoweredbyenginesabletoswitchbetweenair

andliquidoxygen._TheyareknownasSynergeticAirBreathingRocketEngines

(SABRE)andwouldbefuelledbyliquidhydrogen,whichhasatemperatureofless

than20degreesaboveabsolutezero.Thetrick,whenaSABREisinair-breathing

mode,wouldbetousethiscoldnesstoabsorbheatgeneratedbytheinrushingair

beforeitcouldcausedamage.Aheat-exchangerintendedtodothiswas

testedsuccessfullyinApril.(10)Atbest,thechancesofatinyteamworkingin

themetaphoricalequivalentofagardenshedcrackingtheproblemofair-