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802.11b 定义了使用跳频扩频技术的无线局域网标准,传输速率为 1mbps,2mbps,5.5mbps ,()

A、10mbps
B、11mbps
C、20mbps
D、54mbps
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正确答案:

B

答案解析:

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PartIVTranslation

Bymeasuringandchartingtheresultsofmanyexperiments,theyaretryingtofindoutwhatmakesdifferentpeopleperceivetotallydifferentthingsaboutthesamescene.(PassageOne)

翻译:

Thecaptainrealizedthatthementriedtodeceivehimsohemadethemworkveryhardfortherestofthevoyage.(PassageOne)

Whatdoesthefutureholdfortheproblemofhousing?Agooddealdepends,ofcourse,onthemeaningof“future”.Ifoneisthinkingintermsofsciencefictionandthespaceage,itisatleastpossibletoassumethatmanwillhavesolvedsuchtrivialandearthlyproblemsashousing.Writersofsciencefiction,fromH.G.Wellsonwards,havehadlittletosayonthesubject.Theyhaveconveyedthesuggestionthatmenwillliveingreatcomfort,witheveryconceivableapparatustomakelifesmooth,healthyandeasy,ifnothappy.Buttheyhavenotsaidwhathishousewillbemadeof.Perhapssomenewbuildingmaterial,asyetunimagined,willhavebeendiscoveredorinventedatleast.Onemaybecertainthatbricksandmortar(泥灰,灰浆)willlonghavegoneoutoffashion.

Buttheproblemsofthenextgenerationortwocanmorereadilybeimagined.Scientistshavealreadypointedoutthatunlesssomethingisdoneeithertorestricttheworld’srapidgrowthinpopulationortodiscoveranddevelopnewsourcesoffood(orboth),millionsofpeoplewillbedyingofstarvationoratthebestsufferingfromunderfeedingbeforethiscenturyisout.Butnobodyhasyetworkedoutanyplanforhousingthesegrowingpopulations.Admittedlytheworstsituationswilloccurinthehottestpartsoftheworld,wherehousingcanbelightstructureorinbackwardareaswherestandardsaretraditionallylow.Buteventheminimumshelterrequiresmaterialsofsomekindandintheteeming,bulgingtownsthelow-standard“housing”offlattenedpetrolcansanddirtycanvasisfarmorewastefulofgroundspacethancanbetolerated.

Sincethewar,HongKonghassufferedthekindofcrisiswhichislikelytoariseinmanyotherplacesduringthenextgeneration.Literallymillionsofrefugeesarrivedtoswellthealreadygrowingpopulationandemergencystepshadtobetakenrapidlytopreventsqualor(肮脏)anddiseaseandthespreadcrime.Thecityistacklingthesituationenergeticallyandenormousblocksoftenements(贫民住宅)arerisingatanastonishingaped.ButHongKongisonlyonesmallpartofwhatwillcertainlybecomeavastproblemandnotmerelyahousingproblem,becausewhenpopulationgrowsatthisratethereareaccompanyingproblemsofeducation,transport,hospitalservices,drainage,watersupplyandsoon.NoteveryareamaygivethesameresourcesasHongKongtodrawuponandthesearchforquickerandcheapermethodsofconstructionmustnevercease.

1.Whatistheauthor’sopinionofhousingproblemsinthefirstparagraph?

A.Theymaybecompletelysolvedatsometimeinthefuture.

B.Theyareunimportantandeasilydealtwith.

C.Theywillnotbesolveduntilanewbuildingmaterialhasbeendiscovered.

D.Theyhavebeendealtwithinspecificdetailinbooksdescribingthefuture.

2.Thewriterissurethatinthedistantfuture___.

A.bricksandmortarwillbereplacedbysomeotherbuildingmaterial.

B.anewbuildingmaterialwillhavebeeninvented.

C.bricksandmortarwillnotbeusedbypeoplewhowanttheirhousetobefashionable.

D.anewwayofusingbricksandmortarwillhavebeendiscovered.

3.Thewriterbelievesthatthebiggestproblemlikelytoconfronttheworldbeforetheendofthecentury___.

A.isdifficulttoforesee.

B.willbehowtofeedtheevergrowingpopulation.

C.willbehowtoprovideenoughhousesinthehottestpartsoftheworld.

D.isthequestionoffindingenoughgroundspace.

4.Whenthewritersaysthattheworstsituationswilloccurinthehottestpartsoftheworldorinbackwardareas,heisreferringtothefactthatintheseparts___.

A.standardsofbuildingarelow.

B.onlyminimumshelterwillbepossible.

C.thereisnotenoughgroundspace.

D.thepopulationgrowthwillbethegreatest.

5.WhichofthefollowingsentencesbestsummarizesParagraph3?

A.HongKonghasfacedaseriouscrisiscausedbymillionsofrefugees.

B.HongKonghassuccessfullydealtwiththeemergencycausedbymillionsofrefugees.

C.HongKong’scrisiswasnotonlyamatterofhousingbutincludedanumberofotherproblemsofpopulationgrowth.

D.ManypartsoftheworldmayhavetofacethekindofproblemsencounteredbyHongKongandmayfinditmuchhardertodealwiththem.

Passage3

Questions11to15arebasedonthefollowingpassage:

About70millionAmericansaretryingtolossweight.Thatisalmost1outofevery3peopleintheUnitedStates.Somepeoplegoonideas.Thismeanstheyeatlesscertainfoods,especiallyfatsandsugars.Otherpeopleexercisewithespecialequipment,takedietpills,orevenhavesurgery.Losingweightishardwork,anditcanalsocostalotofmoney.SowhydosomanypeopleintheUnitedStateswanttoloseweight?

ManypeopleintheUnitedStatesworryaboutnotlookingyoungandattractive.Formanypeople,lookinggoodalsomeansbeingthin.Otherpeopleworryabouttheirhealth.Manydoctorssaybeingoverweightisnothealthy.ButareAmericansreallyfat?Almost30millionAmericansweightatleast20percentmorethantheiridealweight.Infact,theUnitedStateisthemostoverweightcountryinthewild.“ThestoredfatofadultAmericansweight2.3trillionpounds,”saysUniversityofMassachusettsanthropologist(人类学家)GeorgeArmelagos.Hesaysburningoffthatstoredenergywouldproduceenoughpowerfor900,000carstogo12,000miles.

Losingweightishardwork,butmostpeoplewanttofindafastandeasywaytotakeofffat.Bookstoresselllotsofdietbooks.Thesebookstellreadershowtoloseweight.Eachyear,dozensofnewbookslikethesearewritten.Eachoneboaststohelppeopletogetridoffat.

11.WhichofthefollowingisNOTmentionedasawayoflosingweight?

A.Toeatlessfatsandsugars.B.Toworkhard.

12.ManyAmericansaretryingtoloseweightbecause.

A.theywanttolookattractiveB.theyaremisledbydoctors

C.theywanttokeepfitD.bothAandC

13.Thefiguresgiveninthesecondparagraphsuggestthat.

A.AmericansaredependentoncarsB.carsconsumealotofmoney

C.AmericansneedloseweightD.excessoffatcanbeasourceofenergy

14.Itcanbeinferredfromthelastparagraphthat.

A.dietbooksarenotalwayseffectiveB.dietbooksareusuallyhelpful

C.therearelotsofwaysoflosingweightD.bookstoresarekeepingtheirpromises

15.Itcanbeconcludedfromthepassagethat.

A.peoplethinktoomuchoftheirappearance

B.thereisnotasurewayoflosingweightasyet

C.surgeryisthefastestwayoflosingweight

D.goingondietisasafewayoflosingweight

Rockmusicusually____theyoungpeopleinmostcountries.

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