Whatisthediscussionmainlyabout?A.Howbeescommunicatewitheachotherthroughdancing.B.Howmonkeysusesignlanguagetocommunicate.C.Whetherotheranimalsbesideshumanshavelanguage.D.Howhumancommunicationdiffersfromanimalcommunication.

Whatdoesthestudentwanttodo?

LayersofSocialClassTakentogether,income,occupation,andeducationaregoodmeasuresofpeople'ssocialstanding.Usingalayeredmodelofstratification,mostsociologistsdescribetheclasssystemintheUnitedStatesasdividedintoseveralclasses:upper,uppermiddle,middle,lowermiddle,andlowerclass.Eachclassisdefinedbycharacteristicssuchasincome,occupationalprestige,andeducationalattainment.Thedifferentgroupsarearrayedalongacontinuumwiththosewiththemostmoney,education,andprestigeatthetopandthosewiththeleastatthebottom.IntheUnitedStates,theupperclassownsthemajorshareofcorporateandpersonalwealth;itincludesthosewhohaveheldwealthforgenerationsaswellasthosewhohaverecentlybecomerich.Onlyaverysmallproportionofpeopleactuallyconstitutetheupperclass,buttheycontrolvastamountsofwealthandpowerintheUnitedStates.Theyexerciseenormouscontrolthroughoutsociety.Mostoftheirwealthisinherited.Despitesocialmythstothecontrary,thebestpredictoroffuturewealthisthefamilyintowhichyouareborn.Eachyear,thebusinessmagazineForbespublishesalistofthe"Forbes400"--thefourhundredwealthiestfamiliesandindividualsinthecountry.Ofallthewealthrepresentedonthe"Forbes400"list,morethanhalfisinherited.Thoseonthelistwhocouldbecalled"self-made"werenottypicallyofmodestorigins;mostinheritedsignificantassets(Forbes,1997;SklarandCollins,1997).Thoseintheupperclasswithnewlyacquiredwealthareknownasthenouveauriche.Althoughtheymayhavevastamountsofmoney,theyareoftennotacceptedinto"oldrich"circles.Theuppermiddleclassincludesthosewithhighincomesandhighsocialprestige.Theytendtobewell-educatedprofessionalsorbusinessexecutives.Theirearningscanbequitehighindeedsuccessfulbusinessexecutivescanearnmillionsofdollarsayear.Itisdifficulttoestimateexactlyhowmanypeoplefallintothisgroupbecauseofthedifficultyofdrawinglinesbetweentheupper,uppermiddle,andmiddleclass.Indeed,theuppermiddleclassisoftenthoughtofas"middleclass"becausetheirlifestylesetsthestandardtowhichmanyaspire,butthislifestyleissimplybeyondthemeansofamajorityofpeopleintheUnitedStates.Themiddleclassishardtodefine;inpart,being"middleclass"ismorethanjusteconomicposition.ByfarthemajorityofAmericansidentifythemselvesasmiddleclasseventhoughtheyvarywidelyinlifestyleandinresourcesattheirdisposal.ButtheideathattheUnitedStatesisanopen-classsystemleadsmanytothinkthatthemajorityhaveamiddle-classlifestylebecause,ingeneral,peopletendnottowanttorecognizeclassdistinctionsintheUnitedStates.Thus,themiddleclassbecomestheubiquitousnormeventhoughmanywhocallthemselvesmiddleclasshaveatenuousholdonthisclassposition.Inthehierarchyofsocialclass,thelowermiddleclassincludesworkersintheskilledtradesandlow-incomebureaucraticworkers,manyofwhommayactuallydefinethemselvesasmiddleclass.Examplesareblue-collarworkers(thoseinskilledtradeswhodomanuallabor)andmanyserviceworkers,suchassecretaries,hairdressers,waitresses,police,andfirefighters.Mediumtolowincome,education,andoccupationalprestigedefinethelowermiddleclassrelativetotheclassgroupsaboveit.Theterm"lower"inthisclassdesignationreferstotherelativepositionofthegroupinthestratificationsystem,butithasapejorativesoundtomanypeople,especiallytopeoplewhoaremembersofthisclass.Thelowerclassiscomposedprimarilyofthedisplacedandpoor.Peopleinthisclasshavelittleformaleducationandareoftenunemployedorworkinginminimum-wagejobs.Fortypercentofthepoorwork;10percentworkyear-roundandfulltime--aproportionthathasgenerallyincreasedovertime.Recently,theconceptoftheunderclasshasbeenaddedtothelowerclass.Theunderclassincludesthosewhohavebeenleftbehindbycontemporaryeconomicdevelopments.Rejectedfromtheeconomicsystem,thoseintheunderclassmaybecomedependentonpublicassistanceorillegalactivities.

Reading5"TheEvolutionofBirds"BirdsBeganasFeatheredReptilesBirdsevolvedduringthegreatreptilianradiationoftheMesozoicera.Amnioticeggsandscalesonthelegsarejusttwoofthereptilianfeaturesweseeinbirds.Butmodernbirdslookquitedifferentfrommodernreptilesbecauseoftheirfeathersandotherdistinctiveflightequipment.CharacteristicsofBirds→Almosteverypartofatypicalbird'sanatomyismodifiedinsomewaythatenhancesflight.Theboneshaveaninternalstructurethatishoneycombed,makingthemstrongbutlight.Theskeletonofafrigatebird,forinstance,hasawingspanofmorethan2metersbutweighsonlyabout113grams.Anotheradaptationreducingtheweightofbirdsistheabsenceofsomeorgans.Females,forinstance,haveonlyoneovary.Also,modernbirdsaretoothless,anadaptationthattrimstheweightofthehead.Foodisnotchewedinthemouthbutgroundinthegizzard,adigestiveorgannearthestomach.(Crocodilesalsohavegizzards,asdidsomedinosaurs.)Thebird'sbeak,madeofkeratin,hasproventobeveryadaptableduringavianevolution,takingonagreatvarietyofshapessuitablefordifferentdiets.Flyingrequiresagreatexpenditureofenergyfromanactivemetabolism.Birdsareendothermic;theyusetheirownmetabolicheattomaintainawarm,constantbodytemperature.Feathersand,insomespecies,layersoffatprovideinsulationthatenablesbirdstoretaintheirmetabolicallygeneratedheat.Anefficientrespiratorysystemandacirculatorysystemwithafour-chamberedheartkeeptissueswellsuppliedwithoxygenandnutrients,supportingahighrateofmetabolism.Thelungshavetinytubesleadingtoandfromelasticairsacsthathelpdissipateheatandreducethedensityofthebody.Forsafeflight,senses,especiallyvision,mustbeacute.Birdshaveexcellenteyes,perhapsthebestofallthevertebrates.Thevisualareasofthebrainsarewelldeveloped,asarethemotorareas;flightalsorequiresexcellentcoordination.Withbrainsproportionatelylargerthanthoseofreptilesandamphibians,birdsgenerallydisplayverycomplexbehavior.Avianbehaviorisparticularlyintricateduringbreedingseason,whenbirdsengageinelaborateritualsofcourtship.Becauseeggsareshelledwhenlaid,fertilizationmustbeinternal.Copulationinvolvescontactbetweenthemates'vents,theopeningstotheircloacas.Aftereggsarelaid,theavianembryomustbekeptwarmthroughbroodingbythemother,father,orboth,dependingonthespecies.→Abird'smostobviousadaptationforflightisitswings.Birdwingsareairfoilsthatillustratethesameprinciplesofaerodynamicsasthewingsofanairplane.Providingpowerforflight,birdsflaptheirwingsbycontractionsoflargepectoral(breast)musclesanchoredtoakeelonthesternum(breastbone).Somebirds,suchaseaglesandhawks,havewingsadaptedforsoaringonaircurrentsandflaptheirwingsonlyoccasionally;otherbirds,includinghummingbirds,mustflapcontinuouslytostayaloft.Ineithercase,itistheshapeandarrangementofthefeathersthatformthewingsintoanairfoil.Thefastestbirdsaretheappropriatelynamedswifts,whichcanfly170km/hr.→Inbeingbothextremelylightandstrong,feathersareamongthemostremarkableofvertebrateadaptations.Feathersaremadeofkeratin,thesameproteinthatformsourhairandfingernailsandthescalesofreptiles.Feathersmayhavefunctionedfirstasinsulationduringtheevolutionofendothermy,onlylaterbeingco-optedasflightequipment.Theevolutionofflightrequiredradicalalterationinbodyform,butflightprovidesmanybenefits.Itenhanceshuntingandscavenging:manybirdsexploitflyinginsects,anabundant,highlynutritiousfoodresource.Flightalsoprovidesreadyescapefromearthboundpredatorsandenablessomebirdstomigrategreatdistancestoutilizedifferentfoodresourcesandseasonalbreedingareas.Thebirdthattravelsfarthestinitsannualmigrationisthearctictern,whichfliesround-tripbetweentheNorthPoleandSouthPoleeachyear.→Analysesoffossilizedskeletonssupportthehypothesisthattheclosestreptilianrelativesofbirdswerethetheropods,agroupofrelativelysmall,bipedalcarnivorousdinosaurs.Mostresearchersagreethattheancestorofbirdswasafeatheredtheropod.However,somesoientistsplacetheoriginofbirdsmuchearlier,fromanancestorcommontobothbirdsanddinosaurs.Theintensecurrentinterestintheoriginofbirdswillundoubtedlybringusclosertounderstandinghowthesemastersoftheskyevolvedfromnonflyingreptiles.Glossarybrooding:tohatcheggsbysittingonthenestcloacas:theopeningtothereproductiveandintestinaltract

LichensLichenslooklikesplashesofpaintleftbehindbyacarelesspainter.Unlikemanyplants,theydonotrequiresoiltogrow.Theygrowonthebarkoftreesinsteamingtropicalrainforests,onfarmers'fenceposts,onthebricksofbig-citybuildings,andonoldgravestones.Lichenscantolerateextremesofclimate.Theygrowonrocksinhotsprings,onwind-sweptmountaintopboulders,andonstonesinthedriestdeserts.IntheArctic,lichens,knownasreindeermoss,aretheprincipalsourceoffoodforcaribou.WholemountainsidesinAntarcticaappeargreenandorangebecauseofthepresenceoflichens;theyareoneofthefewplantsthatcansurvivethere.Theyareamongtheoldestofknownplants.Recently,scientistsdiscoveredlichenfossilsonarockinaphosphatemineinSouthwestChinathatdateback600millionyears.Whenconditionsbecomeharsh,lichensbecomedormant.Ifthereisnotenoughmoisture,theysimplydryup,butashortrainorevenaheavydewgivesthemnewlife.Whengrowingonrocksurfaces,lichenssecreteacidsthatdissolvetheminerals,contributingtotheprocessofweatheringbywhichrocksareslowlyturnedtosoil.Thispropertyenableslichenstobepioneers.Theyappearonbarrenrockscouredcleanbyglaciers,fires,lavaflows,orfloods,beginningtheprocessofsoilformationthatallowsmosses,ferns,andotherplantstolatertakeroot.But,despitetheirhardiness,lichensareextremelysensitivetoairborneparticles.That'swhytheyserveasanearlywarningsystemforairpollution.Itistheacidslichensproducethatgivethemtheirdistinctivecolors.Lichensareoftenspokenofinthesamebreathasmosses,andsomelichensareevencalledmosses,buttruemossesarealldistinctivelygreen,whereaslichensappearinmanyvividcolors.Atonetime,beforetheinventionofanilinedyes,acidsfromlichenswereusedtomakedyes,suchasthepurpledyeorchil,thebluedyelitmus,andthereddyecudbear,andtheyaresometimesstillusedthatwaytoday.Somelichens,suchasoakmoss,containoilsthatproducefragrantodorsusedinscentedsoaps,cosmetics,andperfumes.Somelichensarealsoknowntohaveantibioticproperties.Lichensareapartnershipoftwoormoretypesofplants,afungusandatypeofalgae.Ifyoulookatthelichenbodythroughamagnifyingglass,youwillseethatitismadeupofatangledmassoffungalstrandscalledhyphae.Intheupperlayerofthesehyphaegrowcoloniesofanothertypeofplant.Thesearemostcommonlygreenalgaebutaresometimesbluegreenalgae.Thetwotypesoforganismslivetogethertothebenefitofboth,arelationshipknownassymbiosis.Thefungusprovidessupportforthealgaeandprotectsthetenderalgaefromdirectsunlightanddryair.Thefungusprovidesmoistureandmineralsfortheplant.Thefungusalsoproduceschemicalsthat,whencombinedwithalcoholproducedbythealgae,formacidcrystals.Thisacidcarvestinyholesinrocksandothersubstances,andthefungusinsertsthreads(nottrueroots)intotheseholestoanchortheplantinplace.Thealgaecontainchlorophyllandsynthesizesugarsfromcarbondioxideandsunlight,producingfoodforthelichens.Achemicalsecretedbythefungussoftensthecellwallsofthealgaeandallowsnutrientstopassfromthealgaetothefungus.Therearemanyexamplesofsymbiosisinnature,butlichensareuniquebecausetheylookandbehavedifferentlyfromtheircomponents.Thealgalcomponentsoflichenscanliveindependentlyandarerecognizableasspeciesthatgrowalone.Thefungalcomponents,ontheotherhand,cannotliveapartfromtheirpartners.Theycanbeplacedinknownfamiliesoffungibutareunlikeanyspeciesthatliveindependently.Sodefinitearetheform,color,andcharacteristicsofthesedoubleorganismsthatforhundredsofyearslichenswereclassifiedasone.Morethan15,000specieswerenamed.Iftheseorganismsareclassifiedassinglespecies,itisdifficulttofitthemintotheexistingsystemofclassification.Butiftheyareclassifiedasseparatespecies,thesefungalspeciesthatcannotlivealoneseemratherstrange.Lichens,then,areasplendidexampleofthedifficultiesfacedbytaxonomistsinclassifyingspecies.Glossary:fungus:anon-green,plant-likeorganismsuchasamushroomthatfeedsondeadorlivingplantsalgae:asimpleplantthatusuallylivesinwaterchlorophyll:achemicalthatenablesplantstophotosynthesize(usesunshinetocreatefood)

LichensTobecertain,alichenisnotthemostconspicuousofplants.Lichensgrowinunassumingfashiononrocks,logsandotherexposedsurfacesinawiderangeofhabitatsaroundtheworld.Totheuntrainedeyetheylooklikelittlemorethancrustypatchesthat,atfirstglance,mighteasilybemistakenforadiscolorationofthesurface.Eveniftheaveragepersonshouldhappentonoticethelichen'spresenceandcorrectlyidentifyitassomeformoflife,heisunlikelytogomuchfurtherincontemplatingit.Thoughalmosttotallyignoredbythelayperson,forthebotanist,lichensareoneofthemostfascinatingofallplants,andoneofthemostintenselystudied.Theyarethesubjectofsomuchscientificscrutinyprimarilybecausealichenisnotjustoneplant.Itis,infact,acompositeorganismmadeupoffungusandalgaelivingtogetherinacloseassociationthatis,presumably,beneficialtoboth.Whenthesetwoverydifferentplantscombine,theresultisauniqueandverylong-livedcompositeorganismthatappears,atleastonamacroscopicscale,tobeaunitaryplant.Itisanorganismthatbearsnoresemblancetoeitherofitsconstituentswhentheyareobservedindividually.Theseparatefungalandalgaeelementscanberecognizedonlywhenthebodyoftheplant,calledathallusbecausetherearenostemsorroots,issectionedandexaminedunderamicroscope.Whenviewedthisway,thefunguscomponentdominatesthepicture,asitaccountsforninetenthsofthetotalbodymassofthelichen.But,entrappedwithinit,clearlyvisibleasdarkspots,arethealgaecells.Essentially,nothingisknownofhowanamorphousmassoffungiandalgaecometogethertoformahighlydifferentiated,structurallystablebody.Despiteallthescientificscrutinylichenshavereceived,itisstillnotentirelycertainwhateachmembergainsfromtheassociation.Someresearchershavespeculatedthatthefungijoinintherelationshipbecausetheyareabletoconsumethealgaecellsastheydieandthereforeareguaranteedafoodsupply.Itiswell-knownthatthechlorophyll-containingalgaecellsproducefoodbymeansofphotosynthesis.Theremaybesomemechanism,stillunknowntous,throughwhichthisenergysourceisutilizedbythefungus.Funguspossessesnochlorophyllofitsown.Howorevenwhetherthealgaebenefitfromthisassociationisstilllesscertain,thoughwecaneasilyimaginethattheygainmechanicalprotectionfromtheelementsbybeingtightlyenvelopedinthestructuralfibersofthefungusbody.Theyshouldalsobenefitfromretentionofwaterbetweenthefibers.Thehardinessoflichenshasmadethemwhatbotaniststerm"pioneerplants".Thisreferstotheirabilitytocolonizehabitatswhereotherplantsdonotexist.Theyarecommononbarrenrockysurfaces,wherethelackofsoilprecludestheestablishmentofmostotherkindsofplantlife.TheycanevenbefoundinplacesashostileandextremeastheinterioroftheAntarcticcontinent.Althoughtheyaremostoftenassociatedwithfarnorthernorsouthernenvironments,theyhavebeenfoundlivinginsunbakeddesertsoilsthatareotherwisedevoidoflife.ThemosthighlyspecializedlichensaretheendolithicspeciesoftheAntarctic,whichasthenameindicates,liveinsiderocks,formingmoreorlesscontinuoustissuestructuresbetweentherockcrystals.Asremarkableintheirrobustnessaslichensare,thereisonekindofanenvironmentwhichtheyaregenerallyunabletotolerate.Habitatsthatareheavilyaffectedbypollutionarenoticeablydevoidoflichens.Theseorganismsareespeciallysusceptibletosulfurdioxidepoisoningandtheyabsorbandaccumulateothertoxinsaswell;bothairandwaterborne.Thisheightenedsensitivityarisesfromthefactthatlichenshavenomeansofriddingtheirtissuesofthesesubstances.Itisthoughtthatthepollutantsaccumulateanddestroythechlorophyllinthealgaecells,thusdisruptingtherelationshipwiththefungus.Thisparticularcharacteristicmakeslichensanespeciallygoodindicatorofenvironmentalhealth.Surveyscurrentlyindicatethatlichensarecompletelyabsentfromurbancenterswithpopulationsof100,000ormore.

TOEFLReadingPassage1HistoricalChangesintheEuropeanArtWorld1.EuropeanartistsintheLateMiddleAgeswereaccordedthesamesocialstatusasblacksmiths,carpenters,tailors,andothercraftsmen.Whereasphilosophers,musicians,andpoetswereseenasexercisingintellectualskills,artistswerenot.Likeothercraftsmen,theywereorganizedundertheguildsystem.OriginallydevelopedpriortothesecondmillenniumAD,guildswereformalorganizationsfoundedbypeoplewhopracticedasimilarcraft,withtheintentionofensuringtheyreceivedfairpaymentfortheirservicesandfosteringtheexchangeofknowledgeamongmembers.InmostEuropeancities,therewouldbeamasons'guild,asmiths'guild,andacarvers'guild,alongwiththoseestablishedbypainters,sculptors,andarchitects.Newmembersbeganasapprentices,learningfromthemastersoftheircraft,andiftheydemonstratedenoughskill,theywouldonedaybeeligibletobecomemastercraftsmenthemselves.2.Then,inthefourteenthcentury,EuropeenteredaperiodofsignificanttransformationknownastheRenaissance.Thistermliterallymeans"rebirth;'asitdescribesanerawhenEuropeanscholarswererediscoveringworksoftheClassicalGreeksandRomans.Ancienttextsonmath,science,andphilosophy,writtenbysuchfiguresasPlatoandCicero,becamethesubjectsofintensestudyandalteredthewaysinwhichEuropeansViewedtheirworld.FromitsoriginsinFlorence,Italy,theRenaissanceradiatedthroughoutthecontinentandaffectedeveryaspectofthelivesofthepeoplelivingthere.3.ThequestforClassicalknowledgethatcharacterizedtheRenaissancealsoledtoarebirthoftheconceptionoftheartist,Depictionofnatureinitstrueformbecametheideal,andpaintersbegantostudymathematicalperspectiveandopticsinordertomorerealisticallyrepresenttheirsubjects.Thisemphasisonintellectualinvestigationdistinguishedtheartsfromtheso-calledmechanicalcrafts,andartistswitnessedamarkedimprovementintheirsocialstanding.Bythe1500s,descriptionslike"genius"and"divine"werebeingascribedtoMichelangelo,LeonardodaVinci,andothercreatorsofartisticmasterpieces.4.TheRenaissancealsospawnedtheintroductionofformaleducationalinstitutions.Calledacademies,thefirstofthese,suchasthePlatonicAcademyfoundedinFlorencein1438,focusedonliteratureandscientificdisciplines.Soon,though,artisticpursuitswereaddedtothecurriculum,includingeverythingfrompaintingtoarchitecture.Nextcametheriseofacademiesdedicatedsolelytoeducationinthearts.Rome'sAcademyofSt.Luke,establishedin1593,wasoneofthemostpopular,andthesecentersquicklyreplacedtheartists'guildsasthepremierpurveyors*ofartisticknowledge.5.BythecloseoftheRenaissanceinthelateseventeenthcentury,academiesofarthadspreadfromItalynorthtootherregions.Frenchacademiesbecamehighlyinfluential,andtheirmissionshiftedfromgeneraleducationtothecultivationofanationalartists'movement.WhereastheearlyItalianacademieshadnotchargedtheirpupilsorlimitedtheirenrollment,Frenchacademiesinstitutedtuitionandentranceexaminationsystemstoensurethatonlycertainstudentswereadmitted.Controlwasexercisedbythegovernment,andastimewenton,theacademiesdevisedveryspecificartisticconventionsthatitsmemberswereexpectedtofollow.StillemphasizingtheClassicalidealsthathadflourishedduringtheRenaissance,theycametoberegardedasconservativeratherthancreative.Theartworkofacademystudentswasdisplayedinexhibitionsknownassalons,whichwereusuallyopenonlytopeopleofhighsocialstatus.Anyartistwhoseworkwasnotapprovedofbytheacademieswasbarredfromparticipationinthesalons.6.AftertheFrenchRevolution,agradualmovetowardgreaterpublicaccesstoartisticworksbeganwiththeopeningoftheLouvreMuseuminParisin1793.Thisideacaughton,andsoonpublicartmuseumscouldbefoundalloverEurope,looseningtheholdofthepowerfulacademiesontheartworld.Newstylesweremoreeasilymetwithacceptanceandnewavenueswerecreatedthroughwhichtheworkofartiststhattheacademiessawastooradicalcouldbeshown.Subsequently,thenineteenthcenturywitnessedtheintroductionofmanyuniqueartisticstyles,atrendwhichhascontinuedtothepresentday.purveyor*apersonorcompanythatprovidesgoodsorservices

Directions: Read the passage. Then answer the questions. Give yourself 20 minutes to complete this practice set. DEER POPULATIONS OF THE PUGET SOUND Two species of deer have been prevalent in the Puget Sound area of Washington state in the Pacific Northwest of the United States. The black-tailed deer, a low-land, west-side cousin of the mule deer of eastern Washington, is now the most common. The other species, the Columbian white-tailed deer, in earlier times was common in the open prairie country; it is now restricted to the low, marshy islands and flood plains along the lower Columbia River. Nearly any kind of plant of the forest under-story can be part of a deer's diet. Where the forest inhibits the growth of grass and other meadow plants, the black-tailed deer browses on huckleberry, salal, dogwood, and almost any other shrub or herb. But this is fair-weather feeding. What keeps the black-tailed deer alive in the harsher seasons of plant decay and dormancy? One compensation for not hibernating is the built-in urge to migrate. Deer may move from high-elevation browse areas in summer down to the lowland areas in late fall. Even with snow on the ground, the high bushy under-story is exposed; also snow and wind bring down leafy branches of cedar, hemlock, red alder, and other arboreal fodder. The numbers of deer have fluctuated markedly since the entry of Europeans into Puget Sound country. The early explorers and settlers told of abundant deer in the early 1800s and yet almost in the same breath bemoaned the lack of this succulent game animal. Famous explorers of the North American frontier, Lewis and Clark arrived at the mouth of the Columbia River on November 14, 1805, in nearly starved circumstances. They had experienced great difficulty finding game west of the Rockies and not until the second of December did they kill their first elk. To keep 40 people alive that winter, they consumed approximately 150 elk and 20 deer. And when game moved out of the lowlands in early spring, the expedition decided to return east rather than face possible starvation. Later on in the early years of the nineteenth century, when Fort Vancouver became the headquarters for the Hudson's Bay Company, deer populations continued to fluctuate. David Douglas, Scottish botanical explorer of the 1830s, found a disturbing change in the animal life around the fort during the period between his first visit in 1825 and his final contact with the fort in 1832. A recent Douglas biographer states: "The deer which once picturesquely dotted the meadows around the fort were gone [in 1832], hunted to extermination in order to protect the crops." Reduction in numbers of game should have boded ill for their survival in later times. A worsening of the plight of deer was to be expected as settlers encroached on the land, logging, burning, and clearing, eventually replacing a wilderness landscape with roads, cities, towns, and factories. No doubt the numbers of deer declined still further. Recall the fate of the Columbian white-tailed deer, now in a protected status. But for the black-tailed deer, human pressure has had just the opposite effect. Wildlife zoologist Helmut Buechner (1953), in reviewing the nature of biotic changes in Washington through recorded time, says that "since the early 1940s, the state has had more deer than at any other time in its history, the winter population fluctuating around approximately 320,000 deer (mule and black-tailed deer), which will yield about 65,000 of either sex and any age annually for an indefinite period." The causes of this population rebound are consequences of other human actions. First, the major predators of deer—wolves, cougar, and lynx—have been greatly reduced in numbers. Second, conservation has been insured by limiting times for and types of hunting. But the most profound reason for the restoration of high population numbers has been the fate of the forests. Great tracts of lowland country deforested by logging, fire, or both have become ideal feeding grounds for deer. In addition to finding an increase of suitable browse, like huckleberry and vine maple, Arthur Einarsen, longtime game biologist in the Pacific Northwest, found quality of browse in the open areas to be substantially more nutritive. The protein content of shade-grown vegetation, for example, was much lower than that for plants grown in clearings.

THE HISTORY OF COMMUNICATION TECHNOLOGY 1 Communication technology influences the ways in which we think about the world．It changes the things we think about，the symbols we use to form and communicate ideas, and the arenas in which our thoughts develop．In the history of communication, there have been many revolutionary technologies, among them the printing press in the fifteenth century and electronic media in the nineteenth century． 2 The development of writing was a major advancement in the ability to communicate over distances and to preserve information accurately．Writing conveyed knowledge of the arts and sciences, which provided foundations for other areas of investigation．However, before books and the printing press, written language was limited to a few clay tablets and parchment scrolls．It was not until books became available that writing made a major impact．For centuries，books were rare and expensive because each one was handwritten， a process that took several months．The printing press with movable type made it possible to produce hundreds of copies of a book in a single day． 3 The invention of the printing press in 1450 launched a new era in the technology of communication．The printing press opened to large groups of people a body of information that had previously been confined to the educated few. The printing press brought books to the common people, increasing the ranks of the literate．Rapid expansion of the arts and sciences and the use of printed materials required a higher level of education．Education became a formalized institution, and children earned adulthood by achieving literacy．The proliferation of books and reading changed how people thought and what they thought about．Reading entailed the linear organization of ideas, stimulating abstract thought and reasoning．The ability to read required a significant increase in a person's attention span, resulting in a higher degree of intellectual discipline．Higher rates of literacy led society to a broader，more global perspective． 4 Another significant revolution in communication technology began in the nineteenth century with the advent of electronic media．The invention of the telegraph in 1843 signaled a new era in communication technology, the electronic era—so called because the telegraph used electrical signals to carry information along an electrical wire．The telegraph fed society's growing appetite for immediate access to information，and it provided a foundation for Successive technologies：the telephone in 1876．the phonograph in 1878, film and movies in the 1890s, radio in 1919, and television in 1925． 5 As with the earliest handwritten books, radio technology was at first restricted to the educated few, scientists and researchers, but later spread to the greater society．By the 1930s, the middle classes were listening to news, drama, comedy, and musical performances from thousands of miles away．Radio was the first mass broadcast medium and, together with television a few decades later, it was responsible for altering both the pattern and volume of information that flowed into people's homes． 6 The invention of electronic media changed communication more than any other technological event since the development of writing．The spread of electronic media occurred with a speed never seen before，thus intensifying commercial and social interaction．There was a tremendous shift in how people received the information that contributed to their understanding of the world．Voices or pictures could create ideas that appeared authentic—more so than ideas conveyed by the printed word．The graphic, intensely human nature of electronic media enhanced the belief that if it was on the air, it had to be true．

Whatisthetalkmainlyabout?A.Thefunctionofcomputers.B.Theoperationofcomputers.C.Thedisadvantagesofcomputers.D.Theemergenceofcomputercrimes.

Listentopartofalectureinasocialwelfareclass.Nowgetreadytoanswerthequestions.Youmayuseyournotestohelpyouanswer.

FindingLongitudeFromancienttimes,seavoyagerswereabletocalculatelatitudewithreasonableaccuracy.Theydidthisatnightbymeasuringtheangleofthepolestarabovethehorizonandatnoonbymeasuringtheangleofthesunabovethehorizon.However,theproblemofcalculatinglongitude,ordegreeseastorwestofameridianlinerunningnorthtosouthfrompoletopole,wasintractable.Evenonlandthiscalculationwasdifficult.Inthe1600s,anItalianscientistpublishedtablesgivingthetimesoftheeclipsesofJupiter'smoons.Fromthesetablesitwaspossibletocalculatelongitudeeastorwestofagivenpointbycomparingthelocaltimeatwhicheclipseshappenedwiththetimegiveninthetables.Thisbreakthroughdidnot,however,helpoceannavigation.TheunstableconditionsaboardshipsmadepreciseobservationofJupiter'ssatellitesanearimpossibility.Othermethods,includingmeasuringtheobserveddistancebetweenthemoonandparticularstars,gaveflawedresults.Inpractice,marinerstendedtoreverttoasystemcalleddeadreckoning.Thisinvolvedfindingpositionbymeasuringspeedbasedonobservingaknottedropethrownoverboard,andacarefulattentiontochangesofdirectionbasedoncompassreadings.Oftencalculationswereexcessivelyinaccurateleadingtoshipwrecksandfailuretoreachdestinations.In1714afterasmallfleetwaswreckedwithahugelossoflife,theBritishgovernmentestablishedaprizeof20,000poundsforwhoevercouldfindanaccuratemethodofdetermininglongitudeatsea.JohnHarrison,anEnglishclockmaker,thoughtthathecouldbuildareliableclockthatwouldkeeptimeatsea,althoughmostscientistsoftheperioddidnotbelievesuchaclockcouldbebuilt.Theirskepticismwaswellfounded;themovementofaship,theconstantchangesoftemperature,andthemoistconditionsmadeaccuratetimekeepinganimpracticaldream.Nevertheless,Harrisonpersevered.Theideabehindhisapproachwasthatasailorcouldreadthetimeonaclocksetcorrectlyinthehomeport.Onavoyagethetimewouldbecheckedonthatclockatnoon(whenthesunwasatthehighestpoint)ontheship.Everyfourminutesofdifferencewouldindicateonedegreeoflongitude.Harrisonworkedforsevenyearsonhisfirstmarineclock.Thecommitteeresponsibleforjudgingthesuccessofcandidatesfortheprizewasdubiousaboutthedesign,butagreedtoaseatrial.ThistestwassuccessfulenoughthatHarrisonwasawardedmoneytocontinuedevelopment.Twomoreversions,todayknownasH2andH3,werebuiltoverthenextseveralyears.TheH2versionwasnotseatestedduetothedangerofitfailingintoSpanishhandsduringtheWaroftheAustrianSuccession.ThelattercreationwasabandonedbyHarrisonwhenhebecamedissatisfiedwithitsperformance.Harrisonthenworkeddiligentlyforthirteenmoreyearsandproduced,atsixty-sixyearsofage,amasterpieceofingenuity.Thisdifferedgreatlyinappearancefromitsforerunners.Itwasonlyalittleoverfiveinchesindiameter,whereastheotherdesignshadbeenheavyinstrumentsthatneededtobehungfromstouttimbers.Mechanically,itwasalsoaradicallyinnovativedesign,usingoilasalubricantandfinelyworkedwheelsandpinions.Afteratwo-monthtriptoJamaica,H4wasdeterminedtohavelostonlyafewseconds.Intermsofdistance,thisrepresentedonlyaboutoneortwomilesoferror.Clearlythislatestapparatushadproveditselftobethebestcandidateyetfortheprize.Duetoprofessionaljealousybysomecommitteemembers,theprizemoneywaswithheld.Finally,aftermuchdebatetheyagreedtohonorHarrisonwithhalfthesum.MoresuccessfultestsofH4continuedwhileHarrisonworkedonH5,aslightlyimprovedversion.Afterthreemoreyears,Harrison'scasewastakenupbyKingGeorgeⅢ,whohadtestedH5athispalaceandsawhowaccuratelyitperformed.Theinterventionbythekingfinallysecuredtherestoftheprizemoney.Harrisonwaseightyyearsoldandhadspenthalfhislifedesigning,constructing,andimprovinghisseriesofremarkableseagoingtimekeepers.Theachievementhadfinallygivenmarinersanaccuratewaytomeasuretheirexactpositionatsea,thussavinglivesandspeedinglengthyoceanjourneys.

Directions:Readthepassage.Thenanswerthequestions.Giveyourself20minutestocompletethispracticeset.HABITATSANDCHIPMUNKSPECIESThereareeightchipmunkspeciesintheSierraNevadamountainrange,andmostofthemlookprettymuchalike.Buteightdifferentspeciesofchipmunksscurryingaroundapicnicareawillnotbefound.NowhereintheSierradoalleightspeciesoccurtogether.Eachspeciestendsstronglytooccupyaspecifichabitattype,withinanelevationalrange,andtheoverlapamongthemisminimal.TheeightchipmunkspeciesoftheSierraNevadarepresentbutafewofthe15speciesfoundinwesternNorthAmerica,yetthewholeofeasternNorthAmericamakesdowithbutonespecies:theEasternchipmunk.WhyaretheresomanyverysimilarchipmunksintheWest?ThepresenceoftallmountainsinterspersedwithvastareasofariddesertandgrasslandmakestheWestecologicallyfardifferentfromtheEast.TheWestaffordsmuchmoreopportunityforchipmunkpopulationstobecomegeographicallyisolatedfromoneanother,aconditionofspeciesformation.Also,therearemoreextremesinwesternhabitats.IntheSierraNevada,highelevationsareclosetolowelevations,atleastintermsofmileage,butecologicallytheyareverydifferent.Mostecologistsbelievethatancientpopulationsofchipmunksdivergedgeneticallywhenisolatedfromoneanotherbymountainsandunfavorableecologicalhabitat.Thesescatteredpopulationsfirstevolvedintoraces—adaptedtothelocalecologicalconditions—andthenintospecies,reproductivelyisolatedfromoneanother.Thisperiodofevolutionwasrelativelyrecent,asevidencedbythesimilarappearanceofallthewesternchipmunkspecies.EcologistshavestudiedthefourchipmunkspeciesthatoccurontheeasternslopeoftheSierraandhavelearnedjusthowthesespeciesinteractwhileremainingseparate,eachoccupyingitsownelevationalzone.Thesagebrushchipmunkisfoundatthelowestelevation,amongthesagebrush.Theyellowpinechipmunkiscommoninlowtomid-elevationsandopenconiferforests,includingandponderosaandJeffreypineforests.Thelodgepolechipmunkisfoundathigherelevations,amongtheIodgepoles,firs,andhigh-elevationpines.Thealpinechipmunkishigherstill,venturingamongthetalusslopes,alpinemeadows,andhigh-elevationpinesandjunipers.Obviously,therangesofeachspeciesoverlap.Whydon'tsagebrushchipmunksmoveintothepinezones?Whydon'talpinechipmunksmovetolowerelevationsandsharetheconiferforestswithlodgepolechipmunks?Theanswer,inoneword,isaggression.Chipmunkspeciesactivelydefendtheirecologicalzonesfromencroachmentbyneighboringspecies.Theyellowpinechipmunkismoreaggressivethanthesagebrushchipmunk,possiblybecauseitisabitlarger.Itsuccessfullybulliesitssmallerevolutionarycousin,excludingitfromthepineforests.ExperimentshaveshownthatthesagebrushchipmunkisphysiologicallyabletoliveanywhereintheSierraNevada,fromhighalpinezonestothedesert.Thelittlecreatureisapparentlyrestrictedtothedesertnotbecauseitisspecializedtoliveonlytherebutbecausethatistheonlyhabitatwherenoneoftheotherchipmunkspeciescanlive.Thefactthatsagebrushchipmunkstolerateverywarmtemperaturesmakesthem,andonlythem,abletolivewheretheydo.Thesagebrushchipmunkessentiallyoccupiesitshabitatbydefault.Inonestudy,ecologistsestablishedthatyellowpinechipmunksactivelyexcludesagebrushchipmunksfrompineforests;theecologistssimplytrappedalltheyellowpinechipmunksinasectionofforestandmovedthemout.Sagebrushchipmunksimmediatelymovedin,butyellowpinechipmunksdidnotentersagebrushdesertwhensagebrushchipmunkswereremoved.Themostaggressiveofthefoureastern-slopespeciesisthelodgepolechipmunk,afeistyrodentindeed.Itactivelypreventsalpinechipmunksfrommovingdownslope,andyellowpinechipmunksfrommovingupslope.Thereislogicbehindthelodgepole'saggressivedemeanor.Itlivesinthecool,shadedconiferforests,andofthefourspecies,itistheleastabletotolerateheatstress.Itis,inotherwords,thespeciesofthestrictesthabitatneeds:itsimplymustbeinthoseshadedforests.However,ifitshareditshabitatwithalpineandyellowpinechipmunks,eitherorbothofthesespeciesmightoutcompeteit,takingmostoftheavailablefood.Suchacompetitioncouldeffectivelyeliminatelodgepolechipmunksfromthehabitat.Lodgepolessurviveonlybyvirtueoftheiraggression.

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