As the pressure____, the liquid rock is forced up through channels in the resistant rock to the earth’s surface.
A
【句意】随着压力的增强，岩浆通过坚岩里的一些渠道被挤压到地球表面。
【难点】intensify意为“强化，增强”;magnify意为“放大，扩大”;heighten意为“增高，提高”，指高度;deviate意为“越轨，脱离”，常与from连用。
Asthepressure____,theliquidrockisforcedupthroughchannelsintheresistantrocktotheearth’ssurface.
ProjectHopeisanorganization_____raisesmoneytobuildschoolsandbuybooksforpoorchildren.
GreatasNewtonwas,manyofhisideas____todayandarebeingmodifiedbytheworkofscientistsofourtime.
AsGilbertWhite，Darwin，andothersobservedlongago，allspeciesappeartohavetheinnatecapacitytoincreasetheirnumbersfromgenerationtogeneration.Thetaskforecologistsistountangletheenvironmentaandbiologicalfactorsthatholdthisintrinsiccapacityforpopulationgrowthincheckoverthelongrun.Thegreatvarietyofdynamicbehaviorsexhibitedbydifferentpopulationmakesthistaskmoredifficult：sompopulationsremainroughlyconstantfromyeartoyear;othersexhibitregularcyclesofabundanceandscarcity;stillothersvarywildly，withoutbreaksandcrashesthatareinsomecasesplainlycorrelatedwiththeweather，andinothercasesnot.Toimposesomeorderonthiskaleidoscopeofpatterns，oneschoolofthoughtproposesdividingpopulationsintotwogroups.Theseecologistspositthattherelativelysteadypopulationshavedensity-dependentgrowthparameters;thatis，ratesofbirth，death，andmigrationwhichdependstronglyonpopulationdensity.Thehighlyvaryingpopulationshavedensity-independentgrowthparameters，withvitalratesbuffetedbyenvironmentalevents;theseratesfluctuateinawaythatiswhollyindependentofpopulationdensity.Thisdichotomyhasitsuses，butitcancauseproblemsiftakentooliterally.Foronething，nopopulationcanbedrivenentirelybydensity-independentfactorsallthetime.Nomatterhowseverelyorunpredictablybirth，death，andmigrationratesmaybefluctuatingaroundtheirlong-termaverages，iftherewerenodensity-dependenteffects，thepopulationwould，inthelongrun，eitherincreaseordecreasewithoutbound(barringamiraclebywhichgainsandlossescanceledexactly)。Putanotherway，itmaybethatonaverage99percentofalldeathsinapopulationarisefromdensity-independentcauses，andonlyonepercentfromfactorsvaryingwithdensity.Thefactorsmakinguptheonepercentmayseemunimportant，andtheircausemaybecorrespondinglyhardtodetermine.Yet，whetherrecognizedornot，theywillusuallydeterminethelong-termaveragepopulationdensity.Inordertounderstandthenatureoftheecologist’sinvestigation，wemaythinkofthedensity-dependenteffectsongrowthparametersasthesignalecologistsaretryingtoisolateandinterpret，onethattendstomakethepopulationincreasefromrelativelylowvaluesordecreasefromrelativelyhighones，whilethedensity-independenteffectsacttoproducenoiseinthepopulationdynamics.Forpopulationsthatremainrelativelyconstant，orthatoscillatearoundrepeatedcycles，thesignalcanbefairlyeasilycharacterizedanditseffectsdescribed，eventhoughthecausativebiologicalmechanismmayremainunknown.Forirregularlyfluctuatingpopulations，wearelikelytohavetoofewobservationstohaveanyhopeofextractingthesignalfromtheoverwhelmingnoise.Butitnowseemsclearthatallpopulationsareregulatedbyamixtureofdensity-dependentanddensity-independenteffectsinvaryingproportions.
1.Theauthorofthetextisprimarilyconcernedwith
[A]Discussingtwocategoriesoffactorsthatcontrolpopulationgrowthandassessingtheirrelativeimportance.
[B]Describinghowgrowthratesinnaturalpopulationsfluctuateovertimeandexplainingwhythesechangesoccur.
[C]Proposingahypothesisconcerningpopulationsizeandsuggestingwaystotestit.
[D]Posingafundamentalquestionaboutenvironmentalfactorsinpopulationgrowthandpresentingsomecurrentlyacceptedanswer.
2.Itcanbeinferredfromthetextthattheauthorconsidersthedichotomydiscussedtobe
[A]Applicableonlytoerraticallyfluctuatingpopulations.
[B]instrumental，butonlyifitslimitationsarerecognized.
[C]Dangerouslymisleadinginmostcircumstances.
[D]Acompleteandsufficientwaytoaccountforobservedphenomena.
3.tothetext，allofthefollowingbehaviorshavebeenexhibitedbydifferentpopulationsEXCEPT
[A]Roughlyconstantpopulationlevelsfromyeartoyear.
[B]Regularcyclesofincreasesanddecreasesinnumbers.
[C]Erraticincreasesinnumberscorrelatedwiththeweather.
[D]Uncheckedincreasesinnumbersovermanygenerations.
4.Thediscussionconcerningpopulationinthethirdparagraphservesprimarilyto
[A]Demonstratethedifficultiesecologistsfaceinstudyingdensity-dependentfactorslimitingpopulationgrowth.
[B]Advocatemorerigorousstudyofdensity-dependentfactorsinpopulationgrowth.
[C]Provethatthedeathratesofanypopulationareneverentirelydensity-independent.
[D]underlinetheimportanceofevensmalldensity-dependentfactorsinregulatinglong-termpopulationdensities.
5.Inthetext，theauthordoesallofthefollowingEXCEPT
[A]Citetheviewsofotherbiologists.
[B]Defineabasicproblemthatthetextaddresses.
[C]Presentconceptualcategoriesusedbyotherbiologists.
[D]Describetheresultsofaparticularstudy.