ImportanceofVitaminsVitamins,whichcomeinmanydifferenttypesallofwhicharequitediverseinchemicalconfigurationandfunction,canbeanyofseveralorganicsubstancesthatareseparatedintowater-solubleandfat-solublegroups.Originallydefinedasorganiccompoundsobtainableinanormaldietandcapableofmaintaininglifeandpromotinggrowth,vitaminsaredifferrentfromcarbohydrates,fats,andproteinsinfunction,aswellasinthequantitiesinwhichorganismsrequirethem.Socriticalarevitaminstoabody'sessentialstrengthandhealththatiftheyareabsentfromthedietornotproperlyabsorbedbyanorganism,aspecificdeficiencydiseasemaydevelop.Theterm"vitamin"originatedfrom"vitamine",awordfirstusedintheearly19thcenturytodesignateagroupofcompoundsconsideredvitalforlife(thoughtheterm"accessoryfoodfactor"sometimesisusedinterchangeablytorefertothesesubstances).Likeothernutrients,vitaminconsumptionisimperativetokeepourbodiesfunctioningproperly,andifthereisalackofvitaminconsumption,thebodywillfailtoreactinawaythat'sconsideredhealthy.LackofvitaminAwillresultinvariousdisordersthatmostcommonlyinvolvetheeyeandthetissuesaroundit.OneoftheearliestsymptomsofvitaminAdeficiencyisnyctalopia,themedicaltermfornightblindness,whichcausesavisualfailuretoadaptquicklyfromlighttodarknessandaninabilitytoseeinthedark.Thisaspectofvisionisnormallydependentonrhodopsin,aproteinfoundintheeyethatmaintainsitselfonlyinthepresenceofvitaminA;inthelackofvitaminA,rhodopsinwillmalfunction.Theseearliersymptomsarequiteharmlessbutthesideeffectscanbecomeincreasinglyseriousifnottreatedearlyon.Ifthedeficiencyissevereandpersists,especiallyinmalnourishedinfantsandchildren,aconditionknownasxerophthahnia--whentheeyesaresensitivetolight,thesecretionoflubricatingtearsisstopped,andtheeyelidsbecomeswollenanddeveloppus--maydevelop.Furthermore,themucoussurfacesoftheeyemaybecomeeroded,allowinginfectiontosetin,thusleadingtoulcerationandotherdestructivechangesofthecorneaandotherstructuresoftheeye,resultingeventuallyinblindness.EarlysignsofvitaminAdeficiencymayalsobereflectedinchangesinthemembranesofthemouth,throat,andrespiratoryandgenitourinarypassageswheretheliningmembranesbecomemalnourishedanddryandlosetheircilia,thetinyhairlikeprojectionsthatnormallyhelpinclearingawayforeignparticles.ThenaturalimmunesystemisweakenedandifinsufficientintakeofvitaminAisprolonged,theskinmaybecomedryandrough.VitaminAdeficiencymayalsoresultindefectiveboneandteethformationandinpoorgeneralgrowth.However,anexcessiveintakeofvitaminAcanalsocauseseveredamagestothebodycausingasymptomcalled"hypervitaminosisA",whichhappenswhenapersontakesinmorethan150milligramsofvitaminAoveralongperiodoftime;thevitaminsarestoredintheliverandcanreachdangerouslevelbecausetheAvitaminsarenotemployedtomakethebodiesstronger,butrather,storedastoxicmaterial.ExcessiveamountsofvitaminAcancausenausea,drynessofskin,blurredvision,drowsiness,andbonepain.VitaminAcanbefoundinallanimallivers,inmilkproducts,andinmanyyellowandgreenleafyvegetableswhichcontaincarotenes,chemicallyrelatedsubstancesthatareconvertedtovitaminAinthebody.Therearevariousothervitaminsthatthehumanbodyneedsinordertosurvive;theexcessiveintakeofvitaminA,orthelackofintakeofothervitamins,causesdetrimenttothehumanbodyatalltimes,moderationiskey.

{{B}}Narrator{{/B}} Listen to a part of a lecture in a computer class.

Reading3"GeothermalEnergy"→GeothermalenergyisnaturalheatfromtheinterioroftheEarththatisconvertedtoheatbuildingsandgenerateelectricity.TheideaofharnessingEarth'sinternalheatisnotnew.Asearlyas1904,geothermalpowerwasusedinItaly.Today,Earth'snaturalinternalheatisbeingusedtogenerateelectricityin21countries,includingRussia,Japan,NewZealand,Iceland,Mexico,Ethiopia,Guatemala,ElSalvador,thePhilippines,andtheUnitedStates.Totalworldwideproductionisappr0aching9,000MW(equivalenttoninelargemoderncoalburningornuclearpowerplants)—doubletheamountin1980.Some40millionpeopletodayreceivetheirelectricityfromgeothermalenergyatacostcompetitivewiththatofotherenergysources.InElSalvador,geothermalenergyissupplying30%ofthetotalelectricenergyused.However,atthegloballevel,geothermalenergysupplieslessthan0.15%ofthetotalenergysupply.→Geothermalenergymaybeconsideredanonrenewableenergysourcewhenratesofextractionaregreaterthanratesofnaturalreplenishment.However,geothermalenergyhasitsorigininthenaturalheatproductionwithinEarth,andonlyasmallfractionofthevasttotalresourcebaseisbeingutilizedtoday.Althoughmostge0thermalenergyproductioninvolvesthetappingofhighheatsources;peoplearealsousingthelow-temperaturegeothermalenergyofgroundwaterinsomeapplications.GeothermalSystems→TheaverageheatflowfromtheinterioroftheEarthisverylow,about0.06W/m2.Thisamountistrivialcomparedwiththe177W/m2fromsolarheatatthesurfaceintheUnitedStates.However,insomeareas,heatflowissufficientlyhightobeusefulforproducingenergy.Forthemostpart,areasofhighheatflowareassociatedwithplatetectonicboundaries.Oceanicridgesystems(divergentplateboundaries)andareaswheremountainsarebeingupliftedandvolcanicislandarcsareforming(convergentplateboundaries)areareaswherethisnaturalheatflowisanomalouslyhigh.Onthebasisofgeologicalcriteria,severaltypesofhotgeothermalsystems(withtemperaturesgreaterthanabout80℃,or176°F)havebeendefined,andtheresourcebaseislargerthanthatoffossilfuelsandnuclearenergycombined.Acommonsystemforenergydevelopmentishydrothermalconvection,characterizedbythecirculationofsteamand/orhotwaterthattransfersheatfromdepthstothesurface.GeothermalEnergyandtheEnvironment→Theenvironmentalimpactofgeothermalenergymaynotbeasextensiveasthatofothersourcesofenergy,butitcanbeconsiderable.Whengeothermalenergyisdevelopedataparticularsite,environmentalproblemsincludeon-sitenoise,emissionsofgas,anddisturbanceofthelandatdrillingsites,disposalsites,roadsandpipelines,andpowerplants.Developmentofgeothermalenergydoesnotrequirelarge-scaletransportationofrawmaterialsorrefiningofchemicals,asdevelopmentoffossilfuelsdoes.Furthermore,geothermalenergydoesnotproducetheatmosphericpollutantsassociatedwithburningfossilfuelsortheradioactivewasteassociatedwithnuclearenergy.However,geothermaldevelopmentoftendoesproduceconsiderablethermalpollutionfromhotwaste-waters,whichmaybesalineorhighlycorrosive,producingdisposalandtreatmentproblems.→Geothermalpowerisnotverypopularinsomelocationsamongsomepeople.Forinstance,geothermalenergyhasbeenproducedforyearsontheislandofHawaii,whereactivevolcanicprocessesprovideabundantnear-surfaceheat.Thereiscontroversy,however,overfurtherexplorationanddevelopment.NativeHawaiiansandothershavearguedthattheexplorationanddevelopmentofgeothermalenergydegradethetropicalforestasdevelopersconstructroads,buildfacilities,anddrillwells.Inaddition,religiousandculturalissuesinHawaiirelatetotheuseofgeothermalenergy.Forexample,somepeopleareoffendedbyusingthe"breathandwaterofPele"(thevolcanogoddess)tomakeelectricity.Thisissuepointsouttheimportanceofbeingsensitivetothevaluesandculturesofpeoplewheredevelopmentisplanned.FutureofGeothermalEnergyAtpresent,geothermalenergysuppliesonlyasmallfractionoftheelectricalenergyproducedintheUnitedStates.However,ifdeveloped,knowngeothermalresourcesintheUnitedStatescouldproduceabout20,000MWwhichisabout10%oftheelectricityneededforthewesternstates.Geohydrothermalresourcesnotyetdiscoveredcouldconservativelyprovidefourtimesthatamount(approximately10%oftotalU.S.electriccapacity),aboutequivalenttotheelectricityproducedfromwaterpowertoday.

Reading3"NewWomenoftheIceAge"Thestatusofwomeninasocietydependsinlargemeasureontheirroleintheeconomy.ThereinterpretationofthePaleolithicpastcentersonnewviewsoftheroleofwomeninthefood-foragingeconomy.AmassingcriticalandpreviouslyoverlookedevidencefromandtheneighboringsiteofPavlov,researchersOlgaSofter,JamesAdovasio,andDavidHylandnowproposethathumansurvivaltherehadlittletodowithmenhurlingspearsatbiggameanimals.Instead,observesSofter,oneoftheworld'sleadingauthoritiesonIceAgehuntersandgatherersandanarcheologistattheUniversityoflllinoisinChampaign-Urbana,itdependedlargelyonwomen,plants,andatechniqueofhuntingpreviouslyinvisibleinthearcheologicalevidence—nethunting."Thisisnottheimagewe'vealwayshadofUpperPaleolithicmachoguysoutkillinganimalsupcloseandpersonal,"Softerexplains."Nethuntingiscommunal,anditinvolvesthelaborofchildrenandwomen.Andthishaslotsofimplications."→Manyoftheseimplicationsmakeherconservativecolleaguescringebecausetheyraiseseriousquestionsaboutthefocusofpreviousstudies.Europeanarcheologistshavelongconcentratedonanalyzingbrokenstonetoolsandbutcheredbig-gamebones,themostplentifulandbestpreservedrelicsoftheUpperPaleolithicera(whichstretchedfrom40,000to12,000yearsago).Fromtheseanalyses,researchershavedevelopedtheoriesabouthowthesesocietiesoncehuntedandgatheredfood.Mostresearchersruledoutthepossibilityofwomenhuntersforbiologicalreasons.Adultfemales,theyreasoned,hadtodevotethemselvestobreast-feedingandtendinginfants."Humanbabieshavealwaysbeenimmatureanddependent,"saysSofter."Ifwomenarethepeoplewhoarealwaysinvolvedwithbiologicalreproductionandtherearingoftheyoung,thenthatisgoingtoconstraintheirbehavior.Theyhavetoprovisionthatchild.Forfathers,provisioningisoptional."→TotesttheoriesaboutUpperPaleolithiclife,researcherslookedtoethnography,thescientificdescriptionofmodernandhistoricalculturalgroups.Whilethelivesofmodernhuntersdonotexactlyduplicatethoseofancienthunters,theysupplyvaluablecluestouniversalhumanbehavior.Inmanyhistoricalsocieties,Sofferobserves,womenplayedakeypartinnethunting,sincethetechniquedidnotcallforbrutestrengthnordiditplaceyoungmothersinphysicalperil.AmongAustralianaborigines,forexample.Womenaswellasmenknottedthemesh,laboringforasmuchastwoorthreeyearsonafinenet.AmongNativeAmericangroups,theyhelpedlayouttheirhandiworkonpolesacrossavalleyfloor.Thentheentirecampjoinedforcesasbeaters.Fanningoutacrossthevalley,men,women,andchildrenalikeshoutedandscreamed,flushingoutgameanddrivingitinthedirectionofthenet."Everybodyandtheirmothercouldparticipate,"saysSoffer."Somepeoplewerebeating,otherswerescreamingorholdingthenet.Andonceyougotthenetontheseanimals,theywereimmobilized.Youdidn'tneedbruteforce.Youcouldclubthem,hitthemanyoldway."→Peopleseldomreturnedhomeempty-handed.ResearcherslivingamongthenethuntingMbutiintheforestsoftheCongoreportthattheycapturegameeverytimetheylayouttheirwoventraps,scoopingup50percentoftheanimalsencountered."Netsareafarmorevalueditemintheirpanoplyoffood-producingthingsthanbowsandarrowsare,"saysAdovasio.SolethalarethesetrapsthattheMbutigenerallyrackupmoremeatthantheycanconsume,tradingthesurpluswithneighbors.Othernethunterstraditionallysmokedordriedtheircatchandstoreditforleanertimes.→SofterdoubtsthattheinhabitantsofandPavlovweretheonlynetmakersinIceAgeEurope.CampsstretchingfromGermanytoRussiaarelitteredwithanotableabundanceofsmall-gamebones,fromharestobirdslikeptarmigan.Andatleastsomeoftheirinhabitantswhittledbonetoolsthatlookmuchliketheawlsandnetspacersfavoredbyhistoricalnetmakers.Althoughthefullrangeoftheiractivitiesisunlikelyevertobeknownforcertain,thereisgoodreasontobelievethatIceAgewomenplayedahostofpowerfulroles.Andtheresearchthatsuggeststhoserolesisrapidlychangingourmentalimagesofthepast.ForSofterandothers,theseareexcitingtimes.

{{B}}Set2{{/B}}{{B}}MediterraneanDiet{{/B}}TheMediterraneandietisbasedupontheeatingpatternsoftraditionalculturesintheMediterraneanregion.Severalnotednutritionistsandresearchprojectshaveconcludedthatthisdietisoneofthemosthealthfulintheworldintermsofpreventingsuchillnessesasheartdiseaseandcancer,andincreasinglifeexpectancy.ThecountriesthathaveinspiredtheMediterraneandietallsurroundtheMediterraneanSea.Thesecultureshaveeatinghabitsthatdevelopedoverthousandsofyears.InEurope,partsofItaly,Greece,Portugal,Spain,andsouthernFranceadheretoprinciplesoftheMediterraneandiet,asdoMoroccoandTunisiainNorthAfrica.PartsoftheBalkanregionandTurkeyfollowthediet,aswellasMiddleEasterncountrieslikeLebanonandSyria.TheMediterraneanregioniswarmandsunny,andproduceslargesuppliesoffreshfruitsandvegetablesalmostyearroundthatpeopleeatmanytimesperday.Wine,bread,oliveoil,nuts,andlegumesareotherstaplesoftheregion,andtheMediterraneanSeahashistoricallyyieldedabundantquantitiesoffish.InternationalinterestinthetherapeuticqualitiesoftheMediterraneandietbeganbackinthelate1950s,whenmedicalresearchersstartedtolinktheoccurrenceofheartdiseasewithdiet.Dr.AncelKeysperformedanepidemiologicalanalysisofdietsaroundtheworld(epidemiologybeingthebranchofpublichealththatstudiespatternsofdiseasesandtheirpotentialcausesamongpopulations).EntitledtheSevenCountriesStudy,itisconsideredasoneofthegreateststudiesofitskindeverperformed.Init,Keysgathereddataonheartdiseaseanditspotentialcausesfromnearly13,000meninGreece,Italy,Croatia,Serbia,Japan,Finland,theNetherlands,andtheUnitedStates.itconcludedthattheMediterraneanpeopleinthestudyenjoyedsomesignificanthealthadvantages.TheMediterraneangroupshadlowermortalityratesinallagebracketsandfromallcauses,particularlyfromheartdisease.ThestudyalsoshowedthattheMediterraneandietisashighorhigherinfatthanotherdiets,obtainingupto40percentofallitscaloriesfromfat.Ithas,however,differentpatternsoffatintake.Mediterraneancookingusessmalleramountsofsaturatedfatandhigheramountsofunsaturatedfat,mostlyintheformofoliveoil.Saturatedfatsarefatsthatarefoundprincipallyinmeatanddairyproducts,althoughavocados,somenuts,andsomevegetableoilsalsocontainthem.Saturatedfatsareusedbythebodytomakecholesterol,andhighlevelsofcholesterolhavesincebeendirectlyrelatedtoheartdisease.SeveralotherstudieshavevalidatedKeys'findingsregardingthegoodhealthtopeopleinMediterraneancountries.TheWorldHealthOrganization(WHO)showedina1990analysisthatfourmajorMediterraneancountries(Spain,Greece,France,andItaly)havelongerlifeexpectanciesandlowerratesofheartdiseaseandcancerthanotherEuropeancountriesandAmerica.ThedataaresignificantbecausethesameMediterraneansfrequentlysmokeanddon'thaveregularexerciseprogramslikemanyAmericans,whichmeansthatothervariablesmayberesponsible.Scientistshavealsoruledoutgeneticdifferences,becauseMediterraneanswhomovetoothercountriestendtolosetheirhealthadvantages.Thesefindingssuggestthatdietandlifestylearemajorfactors.TheMediterraneandietgainedevenmorenoticewhenDr.WalterWillett,headofthenutritiondepartmentatHarvardUniversity,begantorecommendit.Althoughlow-fatdietswererecommendedforsufferersofheartdisease,groupofMediterraneansinhisstudieshadveryhighintakesoffat,mainlyfromoliveoil.Willettandothersproposedthattheriskofheartdiseasecanbereducedbyincreasingonetypeofdietaryfat--monounsaturatedfat--thetypefoundinoliveoil.Willett'sproposalwentagainstconventionalnutritionalrecommendationstoreduceallfatinthediet.IthasbeenshownthatunsaturatedfatsraisethelevelofHDLcholesterol,whichissometimescalled"goodcholesterol"becauseofitsprotectiveeffectagainstheartdisease.Willetthasalsoperformedstudiescorrelatingtheintakeofmeatwithheartdiseaseandcancer.

American Race to the Moon The roots of America's plan to land a man on the moon can be found outside of the country. Although never directly mentioned in its official motto, the National Aeronautics and Space Administration (NASA) was established as a direct result of the Soviet space program's successful launching of Sputnik 1, the first man-made satellite, on October 4th, 1957. The U.S. Congress, worrying that the country was about to lose its technological edge over the rest of the world, demanded drastic action. Dwight D. Eisenhower, then president, waited only a few months before creating a new government agency responsible for all non-military activity in space. On July 29th, 1958, the president signed the National Aeronautics and Space Act, creating NASA. The outside world continued to have an effect. The technology initially used by NASA came in large part from the German rocket program of the Second World War. Wernher von Braun, who was recruited by the Americans at the end of the war, is today considered the father of the United States space program. NASA began operations on October 1st, 1958, and was made up of four laboratories as well as about eight thousand employees from the already 43-year-old National Advisory Committee for Aeronautics. The history of the new organization can be divided into various phases, each related to a specific program. The first experiments undertaken as part of Program Mercury were designed simply to discover if humans could actually survive a round-trip voyage into space. This involved the construction of 20 spacecraft, each large enough to hold one astronaut. On a very basic level, NASA needed to test what worked and what didn't. They made numerous unmanned launches, many of them resulting in explosions, as well as four separate launch attempts that included small creatures. The first was a small monkey. By 1961, NASA's Program Mercury successfully placed Alan Shepard into space, but for only fifteen minutes. This milestone quickly led to the Apollo Project. The initial idea was to get a human close to the Moon, but not actually on it. There were too many unknowns about the surface of the Moon to plan a safe landing. On February 20th, 1962, John Glenn piloted the Friendship 7 for five hours in orbit around the Earth. NASA had finally learned how to get a human into space, and most importantly, keep him there. This was the crucial step necessary: they had created the ability to stay in space long enough to really figure out what to do there. The objectives of the mission changed drastically, however, when President John E Kennedy told the nation on May 25th, 1961, that America would instead focus on a manned mission to and from the Moon, and that these missions would be possible by the end of the decade. ■(A) Many people worried about the money that would be spent, feeling that it would be better used for other purposes. ■(B) Others continued to see the program in relation to the rest of the world. ■(C) They worried that NASA did not seem to have any valuable military use and openly questioned the idea of spending money on rockets that could not be used to defend the country. ■(D) Kennedy managed to convince both sides of the project's benefits. He assured people that the mission would provide jobs and resources to different states throughout the country as well as specific advances in rocket technology. Kennedy stressed the value of dual-use technology, which could be used for both military and non- military purposes. Instead of sending a person to space and back again, which required only one lift-off from Earth followed by a landing, the Apollo Project now entailed an Earth lift-off, followed by a landing on the Moon, another lift-off, and then a final Earth landing. The Gemini Program, therefore, was created to collect information and perfect techniques that would make the Apollo Project possible. Using a series of eleven orbital flights, NASA was able to show that humans could survive in space for days and that two separate vehicles could meet and join while in orbit. It took eight years and numerous attempts before NASA finally reached its goal. On July 20th, 1969, Buzz Aldrin and Nell Armstrong, members of the Apollo Project, became the first humans to walk on the surface of the Moon.

POPULATION ECOLOGY 1 Population ecology is the science that measures changes in population size and composition and identifies the causes of these fluctuations. Population ecology is not concerned solely with the human population. In ecological terms, a population consists of the individuals of one species that simultaneously occupy the same general area, rely on the same resources, and are affected by similar environmental factors. The characteristics of a population are shaped by its size and by the interactions among individuals and between individuals and their environment. 2 Population size is a balance between factors that increase numbers and factors that decrease numbers. Some factors that increase populations are favorable light and temperature, adequate food supply, suitable habitat, ability to compete for resources, and ability to adapt to environmental change. Factors that decrease populations are insufficient or excessive light and temperature, inadequate food supply, unsuitable or destroyed habitat, too many competitors for resources, and inability to adapt to environmental change. 3 An important characteristic of any population is its density. Population density is the number of individuals per unit, such as the number of maple trees per square kilometer in a county. Ecologists can rarely determine population size by actually counting all individuals within geographical boundaries. Instead, they often use a variety of sampling techniques to estimate densities and total population sizes. In some cases, they estimate population size through indirect indicators, such as the number of nests or burrows, or signs such as tracks or droppings. 4 Another important population characteristic, dispersion, is the pattern of spacing among individuals within the population"s geographical boundaries. Various species are distributed in their habitats in different ways to take better advantage of food supplies and shelter, and to avoid predators or find prey. Within a population"s range, densities may vary greatly because not all areas provide equally suitable habitat, and also because individuals space themselves in relation to other members of the population. 5 Individuals may be spread across the environment in three possible dispersion patterns: clumped, uniform, or random. A clumped dispersion means that individuals are gathered in patches throughout their habitat. Clumping often results from the irregular distribution of resources needed for survival and reproduction. For example, fallen trees keep the forest floor moist, and many forest insects are clumped under logs where the humidity is to their liking. Clumping may also be associated with mating, safety, or other social behavior. Crane flies, for example, swarm in great numbers, a behavior that increases mating chances, and some fish swim in large schools so they are less likely to be eaten by predators. 6 A uniform dispersion means that the members of a population are evenly spread throughout their habitat. Uniform spacing occurs when individuals are able to survive anywhere in their habitat, but must also interact directly with other individuals in the population. For example, regular spacing of plants may result from shading and competition for water. In animal populations, uniform distribution is usually caused by competition for some resource or by social interactions that set up individual territories for feeding, breeding, or resting. Individuals use the resources found immediately around them and spread out to use all of the available resources. 7 While clumping and uniform patterns occur where there are direct interactions among individuals, random spacing may be seen where neither strong attraction nor strong repulsion exists among individuals in a population. In random dispersion, individuals are spread throughout their habitat in an unpredictable, irregular manner. Each individual"s location is independent of the locations of other individuals. In tropical rain forests, trees of the same species can be randomly dispersed. Overall, random patterns are rare in nature, with most populations showing a tendency toward either clumped or uniform distribution. Populations change in size, structure, and distribution as they respond to changes in environmental conditions. Four main variables—births, deaths, immigration, and emigration—determine the rate of change in the size of the population over time. A change in the birth rate or death rate is the major way that most populations respond to changes in resource availability. Members of some animal species can avoid or reduce the effects of environmental stress by emigrating from one area and immigrating to another with more favorable environmental conditions, thus altering the population"s dispersion.

{{B}}Set 2{{/B}} POLITICAL SYSTEMS OF THE TWENTIETH CENTURY1 Monarchy is a form of government in which authority is held by a single person, a monarch, whose right to rule is generally hereditary and lifelong. At the start of the twentieth century, monarchs ruled over most of the world, but by the middle of the century, only a handful remained. A series of revolutions in the preceding centuries had weakened the European monarchies, and while monarchs remained symbols of national unity, real power had passed to constitutional assemblies. Monarchy survived as a form in Europe only where the king or queen functioned as the symbolic head of a parliamentary state, as in Britain, the Low Countries, and Scandinavia. It lasted longer in the few small states of Asia and Africa that had never come under direct colonial rule. By the 1960s, autocratic monarchy had become an outdated form of government. Throughout most of the world, people were considered citizens, not subjects, and the totality of the people were seen as constituting the state. 2 In most states where monarchical authority was removed, some form of liberal democracy took its place. A liberal democracy is a state where political authority rests in the people acting through elected representatives and where an elected executive is responsible to the will of the people as a whole. {{U}}The term{{/U}} applies to a broad group of states with a parliamentary or representative political tradition. Liberal democracies differ from the communist states known as {{U}}people's democracies{{/U}}, in which the Communist party holds the ultimate authority. Generally, liberal democracies follow the parliamentary {{U}}pattern{{/U}}, with the executive power vested in a cabinet responsible to the parliament and drawn from the majority party or combination of parties. In the United States, an independently elected executive, the president, functions separately from the legislative authority, the congress. 3 The doctrine that all of the people had effective authority, or sovereignty, became the basis for the functioning of democratic states. This doctrine of popular sovereignty became all-inclusive as citizenship rights were extended to classes formerly excluded and to women. The liberal democratic state claimed the right to control every aspect of human life according to the will of the people, except where limits on state control were directly stated in a bill of rights in a democratic constitution and recognized in practice. 4 All democratic states, both parliamentary and presidential, changed in form during the twentieth century. To meet the needs of an urban industrial society, states generally enlarged their scope of activity to control economic power and to provide common services to the people. The expansion of state activity and extension of state services involved a new view of legislation and its role in society. The passing of laws came to be seen as a way to promote the well being of the people. With this new concept of legislation, the number of new laws increased immensely, particularly in the areas of social welfare, education, health and safety, and economic development. 5 The trend toward liberal democracy continued throughout the century, but at various times there was also a tendency toward a revival of authoritarian rule. In a number of states, democratic governments could not cope with the crises of the time. {{U}}In these cases, some form of totalitarian dictatorship emerged, replacing popular sovereignty with the total power of the state. {{/U}}In some instances, monarchy gave way directly to dictatorship. In others, dictatorial regimes took over democratically organized states, notably in Eastern Europe in the years between the two world wars, in new states of Asia and Africa in the 1950s, and sporadically in Central and South America. 6 Authoritarian governments showed three principle characteristics. First, there was a head of state or leader with exceptional powers, with a party to support him. Second, the legislative body was elected by a system that prohibited parties opposed to the regime, and third, there was a bureaucratic administration that was in no way subject to popular control. The most extreme position on these points was taken by Hitler's totalitarian National Socialist State in the 1930s. Glossary: autocratic: characterized by unlimited power autocratic: characterized by complete obedience to authority, lacking individual freedom

MASS WASTING PROCESSES 1 The downslope movement of rock, mud, or other material under the influence of gravity is known as mass wasting. While the angle of the slope is a major factor in the potential for mass wasting, the slope is not the sole determiner of mass wasting events. Water plays a significant role, especially where it is plentiful during the rainy season. Earthquakes may cause rockslides, mudflows, and other mass movements. Factors such as the presence or absence of vegetation and human activities can also influence the potential for mass wasting. 2 One way to classify mass wasting processes is on the basis of the material involved, such as rock, debris, earth, or mud. The manner in which the material moves is also important and is generally described as a fall, a slide, or a flow. A fall occurs when weathering loosens boulders from cliffs or rock faces, causing the boulders to break away and fall. A slide takes place whenever material remains fairly coherent and moves along a well-defined surface. A flow involves the movement of debris containing a large amount of water. 3 Many mass wasting processes are described as slides. Rockslides occur when a coherent mass of rock breaks loose and slides down a slope as a unit. If the material involved is mostly separate pieces, it is called a debris slide. Slides are among the fastest and most destructive mass movements. Usually rockslides occur in a geologic setting where the rock layers are inclined, or where there are joints and fractures in the rock that are parallel to the slope. When such a rock unit is undercut at the base of the slope, it loses support and the rock eventually collapses. Rain or snowmelt can trigger a rockslide by wetting the underlying surface to the point that friction can no longer hold the rock in place. The fastest type of slide is a rock avalanche, in which a mass of rock literally floats on air as it moves downslope. The high speed of a rock avalanche is the result of air becoming trapped and compressed beneath the falling mass of debris, allowing it to move down the slope as a buoyant sheet. 4 Mudflows are relatively rapid mass wasting events that involve soil and a large amount of water. Because of their fluid properties, mudflows follow canyons and stream channels. Mudflows often take place in semiarid mountainous regions and on the slopes of some volcanoes. Although rainstorms in semiarid regions are infrequent, they are typically heavy when they occur. When a rainstorm or rapidly melting snow creates a sudden flood, large quantities of soil and loose rock are washed into nearby stream channels because there is usually little or no vegetation to anchor the surface material. The result is a flowing mass of well-mixed mud, soil, rock, and water. The consistency of the mudflow may be similar to that of wet concrete, or it may be a soupy mixture not much thicker than muddy water. The water content influences the rate of flow across the surface. When a mudflow is dense, it moves more slowly, but it can easily carry or push large boulders, trees, and even houses along with it. 5 In dry mountainous areas such as southern California, mudflows are a serious hazard to development on and near canyon hillsides. The removal of native vegetation by brush fires has increased the probability of these destructive events. Past mudflows have contributed to the buildup of fan-shaped deposits at canyon mouths. Such fans are relatively easy to build on and often have scenic views, so many have become desirable sites for residential development. However, because mudflows occur infrequently, homeowners are often unaware of the potential danger of building on the site of a previous mudflow. 6 Highly fluid, fast-flowing mudflows incorporate fine-grained sediment and are common after volcanic eruptions that produce large volumes of volcanic ash. Mudflows containing volcanic debris are called lahars, a word originating in Indonesia, a region that experiences many volcanic eruptions. Lahars occur when highly unstable layers of ash and debris become saturated with water and flow down steep volcanic slopes along stream channels. In the northwestern United States, the eruption of Mount St. Helens in 1980 created several lahars that raced down the valley of the Toutle River, altering the landscape in a relatively short period.

TOEFLReadingPassage1TwoTypesofSocialGroups1.Oneofthemostbasicelementsofhumanlifeisthewayinwhichweformsocialgroupsandinteractwiththemembersofthosegroups.Accordingtosociologists,nooneiseverentirelyseparatefromthesocialnetworksthatsurroundhimorher,andthegroupswebelongtoplayanenormousroleindetermininghowweseeourselvesandourworld.EarlyAmericansociologistCharlesH.Cooley(1864-1929)definedtwoprincipalcategoriesofhumangroupings,andhisideasarestillwidelyacceptedtoday.Hetermedthemprimaryandsecondary,basedonthekindsofrelationshipsindividualsinthegroupsharewitheachother.2.Inprimarygroups,weformwhatCooleyreferredtoasprimaryrelationships.Thesearemarkedbystrong,long-lastingemotionalties,feelingsofintimacyandgenuineconcernforthewell-beingoftheotherpersonorpeople.Intangibleitems,suchaslove,respect,andsupport,areexchangedbyindividualsinprimarygroups,causingthemtofeelnurturedbytherelationshipsthegroupaffordsthem.Participationinthegroupisthereforeseenasitsownreward;thereisnoconcrete,externalgoalthatmembersareworkingtowards.3.Duetothetimeandeffortittakestobuildsuchclosebonds,primarygroupsaretypicallysmall.SomeprominentexamplesgivenbyCooleyincludefamilies,groupsofchildhoodfriends,andthetight-knitcommunitiesadultsenterintowiththeirneighborsorotherclosepeers.IntheviewofCooleyandlatersociologists,itistheprimarygroupthatismostimportantinthedevelopmentofanindividual'spersonalbeliefsandvalues,andassiststhatpersonwithhisorherintegrationintosocietyatlarge.4.Secondarygroups,incontrast,arecharacterizedbythelackofintimaterelationshipsamongtheirmembers.Thesesecondaryrelationshipsinvolvelesspersonalinteractionandweakeremotionalconnections,andthereforetheydonothaveassignificantanimpactonthedevelopmentofanindividual'sworldview.Inaddition,sincetiesbetweenindividualsarenotasstrong,manysecondarygroupseitherexistforonlyashorttimebeforedissolving,orexperiencefrequentchangesinmembership.5.Secondarygroupscanbequitelarge.Acompany'semployees,auniversity'sstudentbody,andevenacountry'scitizensareallexamplesofsecondarygroups.Theitemsindividualsexchangeareusuallytangibleinnature,suchasthelaborprovidedinreturnforwagesinthecaseofacommercialorganization.Mostnotably,though,thereasonthatsecondarygroupsforminthefirstplaceistoaccomplishaspecifictask.Employeesparticipateinthesecondarygroupoftheircompanywiththeintentionofcreatingaproductorservice,aswellastoreceivepay.lfthegroupfailstoachieveitsgoal,itwillmostlikelyceasetoexist.6.Cooleybelievedthatbothprimaryandsecondarygroupsareuniversaltohumansocieties.Whilemodernsociologistsagreewiththis,theyhavealsoobservedthattheratioofprimarytosecondarygroupsvariesaccordingtothelevelofasociety'stechnologicaldevelopment.Inless-developednations,individualsspendmostoftheirlivesinasinglelocationwithprolongedexposuretoacertaingroupofpeople.Thisenablesthemtodevelopclosebondsmoreeasily,soprimarygroupsarecommonplace.Developedcountries,ontheotherhand,havewitnessedanincreaseinsecondarygroupsattheexpenseofprimarygroups.Thefastpace,widespreadtechnologyanddiversityoflifeinthesesocietiesmakeitharderforpeopletoconnectemotionallywitheachother.Instead,innovationssuchasInternetchatroomsandconvenienttransportationhaveexpandedthenumberofsecondarygroupsthatpeopleindevelopedsocietiesbelongto.7.Whiletheeffectsofsuchalossofprimarygroupsisnotyetfullyunderstood,someresearchersbelieveitexplainsmanyofthesocialproblemsfacedbysuchsocieties.Therolethatprimarygroupsplayinsocialandemotionaldevelopmentissoimportantthat,iftraditionalprimarygroupsfailtoprovideindividualswithanenvironmentinwhichtheycanexperiencethisgrowth,theymayseekitelsewhere.Theformationofstreetgangs,theuseofillegaldrugs,andotherdetrimentallifestylesseenindevelopedsocietiesmayrepresentfailedattemptstofillthevoidleftbythedisappearanceofprimarygroups.

"ConquestbyPatents"→Patentsareaformofintellectualpropertyrightsoftentoutedasameanstogive"incentiveandreward"toinventors.Butthey"realsoacauseformassiveprotestsbyfarmers,numerouslawsuitsbytransnationalcorporationsandindigenouspeoples,andcountlessralliesanddeclarationsbymembersofcivilsociety.Itisimpossibletounderstandwhytheycanhavealltheseeffectsunlessyoufirstrecognizethatpatentsareaboutthecontroloftechnologyandtheprotectionofcompetitiveadvantage.LessonsfromHistoryInthe1760s,theEnglishmanRichardArkwrightinventedthewater-poweredspinningframe,amachinedestinedtobringcotton-spinningoutofthehomeandintothefactory.ItwasaninventionwhichmadeBritainaworld-classpowerinthemanufactureofcloth.ToprotectitscompetitiveadvantageandensurethemarketformanufacturedclothinBritishcolonies,ParliamentenactedaseriesofrestrictivemeasuresincludingtheprohibitionoftheexportofArkwrightmachineryortheemigrationofanyworkerswhohadworkedinfactoriesusingit.From1774on,thosecaughtsendingArkwrightmachinesorworkersabroadfromEnglandweresubjecttofinesand12yearsinjail.→In1790,SamuelSlater,whohadworkedforyearsintheArkwrightmills,leftEnglandfortheNewWorlddisguisedasafarmer.Hetherebyenabledtheproductionofcommercial-gradecottonclothintheNewWorldandputtheU.S.firmlyontheroadtotheIndustrialRevolutionandeconomicindependence.Slaterwashighlyrewardedforhisachievement.Heisstilldeemedthe"fatherofAmericanmanufacturing".TotheEnglish,however,hewasanintellectualpropertythief.Interestingly,patentprotectionwasapartofU.S.lawatthetimeofSlater"sdeed.ButthatprotectionwouldonlyextendtoU.S.innovations,Itisworthrememberingthatuntilthe1970sitwasunderstood,evenaccepted,thatcountriesonlyenforcedthosepatentprotectionsthatservedtheirnationalinterest.WhentheyoungUnitedStatespiratedtheintellectualpropertyofEurope-andSlaterwasn"ttheonlyinfringer-peopleintheUSsawthetheftasajustifiableresponsetoEngland"srefusaltotransferitstechnology.Bytheearly1970s,thesituationhadchanged.U.S.industrydemandedgreaterprotectionforitsidea-basedproducts-suchascomputersandbiotechnology-forwhichitstillheldtheworldwidelead.Togetherwithitslike-mindedindustrialallies,theU.S.pushedfortheinclusionofintellectualpropertyclauses,includingstandardsforpatents,ininternationaltradeagreements.WhenU.S.businessgroupsexplainedthe"need"forpatentsandtrade-marksintradeagreements,theyalleged$40-60billionlossesduetointellectualpropertypiracy;theyblamedthelossesonThirdWorldpirates;theydiscussedhowpiracyunderminedtheincentivetoinvest;andtheyclaimedthatthequalityofpiratedproductswaslowerthantherealthingandwascostinglives.→Theoppositionpointedoutthatmanyoftheproductsmadeintheindustrialworld,almostallitsfoodcropsandahighpercentageofitsmedicineshadoriginatedinplantandanimalgermplasmtakenfromthedevelopingworld.First,knowledgeofthematerialandhowtouseitwasstolen,andlaterthematerialitselfwastaken.Forallthis,theysaid,barelyacentofroyaltieshadbeenpaid.Suchunacknowledgedanduncompensatedappropriationtheynamed"biopiracy"andtheyreasonedthattradeagreementpatentruleswerelikelytofacilitatemoretheftoftheirgeneticmaterials.Theirclaimthatmaterials"collected"inthedevelopingworldwerestolen,elicitedacounterclaimthatthesewere"natural"or"raw"materialsandthereforedidnotqualifyforpatents.Thisinturninducedacounter-explanationthatsuchmaterialswerenot"raw"butrathertheresultofmillenniaofstudy,selection,protection,conservation,developmentandrefinementbycommunitiesofMajorityWorldandindigenouspeoples.Otherspointedoutthattradeagreementswhichforcedtheadoptionofunsuitablenotionsofpropertyandcreativity-nottomentionanintolerablecommercialrelationshiptonature-werenotonlyinsultingbutalsoexceedinglycostly.Toadevelopingworldwhosecreationsmightnotqualifyforpatentsandroyalties,therewasfirstofallthecostofunrealizedprofit.Secondly,therewasthecostofaddedexpenseforgoodsfromtheindustrializedworld.Formostofthepeopleontheplanet,thewholepatentingprocesswouldleadtogreaterandgreaterindebtedness;forthem,thetradeagreementswouldamountto"conquestbypatents"-nomatterwhatthepurportedcommercialbenefits.Glossaryintellectualproperty:aninventionorcompositionthatbelongstothepersonwhocreatedit

THE NORSE IN NORTH AMERICA 1 The Norse made the first documented European voyages to North America, and there is evidence of these visits in the medieval sagas, a collection of stories that tell the history of the Icelandic people．The Icelandic sagas relate how the Norse captain Leif Eriksson and his brother Thorvald were blown off course during a voyage from Norway to Greenland and landed to the west of Greenland, and also describe Thorfinn Karlsefni's attempt to colonize a place called Vinland．The sagas are a valuable source of details about these early voyages; however, historians have long expressed skepticism about their accuracy． 2 Norsemen ventured far from their homeland in Scandinavia to found settlements on the Greenland coast．One of them, the trader Bjarni Herjolfsson, was blown off course and subsequently discovered a wooded coastline, almost certainly that of Newfoundland． A1though Herjolfsson did not go ashore, this discovery made him the first European to set eyes on the continent of North America． 3 Herjolfsson's account encouraged Leif Eriksson to undertake a southward voyage of exploration, starting around the year 1000．In the course of his travels, Eriksson landed in a place he called Stoneland, which was probably the rocky, barren Labrador coast of North America．Eriksson's party finally landed in Vinland, where they spent a winter in rough Viking huts in a seemingly frost—free land of abundant vines and wild grapes．They established the first European colony in North America at Vinland, the precise location of which remains a subject of scholarly dispute to this day．The Norsemen returned home in the spring，abandoning the rude settlement that, a few years later, would serve as home base for Thorfinn Karlsefni of Greenland． 4 Around 1004, the expedition led by Thorfinn Karlsefni set off southward, evidently with a longer stay in mind, as women and cattle accompanied the sailors．Karlsefni and his party passed two years in Vinland, exploring the coast and fighting the local aboriginal tribes, whom they called "skrelings." Thorfinn Karlsefni was killed in a bloody encounter with a native group．and continued threats from hostile tribes may have thwarted the Norse attempt at colonization．For some reason, they departed their settlement at Vinland, although Greenlanders continued to make occasional visits there in later years, using it as a fishing camp． 5 Until the twentieth century, the Icelandic sagas were the primary source of information about the Norse exploration of North America．They served as inspiration for Norwegian explorer and writer Helge Ingstad, who in the early 1960s traveled the coasts of eastern North America searching for evidence of Vinland．Encouraged by an alternative interpretation of"vin"as meaning"meadow"rather than vine or wine, he discovered a grassy site on the northern tio of Newfoundland that local people had believed was an aboriginal site haunted by ancient ghosts．There, Ingstad excavated the remains of eight sod huts, together with artifacts of Norse origin such as a bronze pin and sewing tools．He concluded that the grassland called L' Anse aux Meadows was, if not Vinland, then certainly a Norse settlement of some kind． 6 Huddled for protection from the wind, the cluster of sod—built structures at L'Anse aux Meadows was no temporary camp．Sod walls and sod roofs built over a timber frame indicated dwellings that were substantial enough for permanent occupation．The eight huts included three long．narrow buildings with features similar to those found in Norse structures in Greenland and Iceland．Other smaller buildings, probably used for storage and workshops, included a forge that used iron ore extracted from peat bogs—evidence of the first iron working in North America． Glossary： sod：soil held together by the roots of grass

Listentopartofalectureinalawclass.Nowgetreadytoanswerthequestions.Youmayuseyournotestohelpyouanswer.

Narrator Listen to a talk between two students. Now get ready to answer the questions. You may use your notes to help you answer.

Listening7"Bookstore"

THE ATLANTIC COD FISHERY 1 Off the northeastern shore of North America, from the island of Newfoundland in Canada south to New England in the United States, there is a series of shallow areas called banks. Several large banks off Newfoundland are together called the Grand Banks, huge {{U}}shoals{{/U}} on the edge of the North American continental shelf, where the warm waters of the Gulf Stream meet the cold waters of the Labrador Current. As the currents brush each other, they stir up minerals from the ocean floor, providing nutrients for plankton and tiny shrimp-like creatures called krill, which feed on the plankton. Herring and other small fish rise to the surface to eat the krill. Groundfish, such as the Atlantic cod, live in the ocean's bottom layer, congregating in the shallow waters where they prey on krill and small fish. {{U}}This rich environment has produced cod by the millions and once had a greater density of cod than anywhere else on Earth.{{/U}} 2 Beginning in the eleventh century, boats from the ports of northwestern Europe arrived to fish the Grand Banks. For the next eight centuries, the entire Newfoundland economy was based on Europeans arriving, catching fish for a few months in the summer, and then taking fish back to European markets. Cod laid out to dry on wooden "flakes" was a {{U}}common{{/U}} sight in the fishing villages dotting the coast. Settlers in the region used to think the only sea creature worth talking about was cod, and in the local speech the word "fish" became synonymous with cod. {{U}}Newfoundland's national dish{{/U}} was a pudding whose main ingredient was cod. 3 By the nineteenth century, the Newfoundland fishery was largely controlled by merchants based in the capital at St. John's. They marketed the catch supplied by the fishers working out of more than 600 villages around the long coastline. In return, the merchants provided fishing equipment, clothing, and all the food that could not be grown in the island's thin, rocky soil. This system kept the fishers in a continuous state of debt and dependence on the merchants. 4 Until the twentieth century, fishers believed in the cod's ability to {{U}}replenish{{/U}} itself and thought that overfishing was impossible. However, Newfoundland's cod fishery began to show signs of trouble during the 1930s, when cod failed to support the fishers and thousands were unemployed. The slump lasted for the next few decades. Then, when an international agreement in 1977 established the 200-mile offshore fishing limit, the Canadian government decided to build up the modern Grand Banks fleet and make fishing a viable economic base for Newfoundland again. All of Newfoundland's seafood companies were merged into one conglomerate. By the 1980s, the conglomerate was prospering, and cod were {{U}}commanding{{/U}} excellent prices in the market. Consequently, there was a significant increase in the number of fishers and fish-processing plant workers. 5 However, while the offshore fishery was prospering, the inshore fishermen found their catches dropping off. In 1992 the Canadian government responded by closing the Grand Banks to groundfishing. Newfoundland's cod fishing and processing industries were shut down in a bid to let the vanishing stocks recover. The moratorium was extended in 1994, when all of the Atlantic cod fisheries in Canada were closed, except for one in Nova Scotia, and strict quotas were placed on other species of groundfish. Canada's cod fishing industry collapsed, and around 40,000 fishers and other industry workers were put out of work. 6 Atlantic cod stocks had once been so plentiful that early explorers joked about walking on the backs of the {{U}}teeming{{/U}} fish. By 2008, cod stocks were still at historically low levels and showed no signs of imminent recovery, even after drastic conservation measures and severely limited fishing. Some fishermen blamed the diminished stocks on seals, which prey on cod and other species, but scientists believe that decades of overfishing are to blame. There have been occasional signs of hope. For example, studies on fish populations show that cod disappeared from Newfoundland at the same time that stocks started rebuilding in Norway, raising the possibility that the cod had simply migrated to a different region. Still, in the early twenty-first century, it remains uncertain whether or when the cod will return to the Grand Banks or the moratorium will end.