Section Three Cause and Effect（第1页）

SeThreedEffect

deffeescalledalysis，exploresthed-effectrelatiowo（ormore）subjes。Whenyoudiscussthereassomething，youareanalyzingtheyoudiscusstheresultsproduething，youareanalyzi。Aalysisessayusuallyfoeitherthecausesortheeffectsofasituatio。hefollowingtwomodelessaysbelow，aifywhichessayfodwhichessayfoeffects。

ModelEssayOne

&ionofDinosaurs

Foralmost140millionyears，dinosaursandereptilesruledtheland，skyandsea。Dinosaurssizesaedtoeveryeroftheworld。Thenapproximately65millio，thesehugereptilesdiedoutandmammalstookovertheEarth。Fewmysterieshaveeverexcitedtheimaginatiosasmuchasthisgreatextinthatkilledoffallthedinosaurs。Overtheyears，stistshavedevelopedheoriestoexplainthecausesofthedisappearahedinosaursareptiles。ThreepossiblecausesareatheEarth'sclimate，disease，ah'swithalargeasteroid（小行星）。

&istsbelievethatthenumberofdinosaursdedeventuallydisappearedduetoatheEarth'sclimate。Duriaceous（白垩纪的）period，theclimateical。Researdicatesthatattheeaceousperiod，thetemperaturedroppedaebecamemuchcolder。Forthisreason，mahattheplaingdinosaursatedied。Thedeathoftheplantswouldyoftheplaodie，too。Astheplaingdinosaursdiedoff，sodidthemeat-eaterswhofedoheatemayhavesforthedinosaursioo。Becauseoftheirsize，manydioobigtohibernateindens（洞穴）。Theyalsolackedfurorfeathersforproteagainstthecold。Asaresult，thedinosaurswereutothenewditions。

Anotherpossiblecausefortheextinofdinosaursisdisease。Somestiststhinkthatsofdinratedadbridges，theyiedohnewillnessesatis，andweresubsequentlykilledoff。AstheCretaceousperiodwenton，moreandmorelaedtoappearoh。Becausetheupanddiowalkacrossthelaheybegantospreadne>

Athirdcausefortheextinofdinosaursistheasteroidthetothistheory，theextinuchmoresuddenandcatastrophithelate1970s，stistsdiscoveredevideheabruptendtotheAgeofDinosaurs。Dr。LouisAlvarezandhiscolleaguesarrivedatarevolutionaryhypothesistoexplaiionofdinosaurs。Theysuggestedthatabout65millio，theEarthwasstruckbyahugeasteroid。Theasteroidwasdestroyedintheexplosion，andbillionsoftonsofdustwerethrownupihickcloudofdustblockedoutsunlightftime。tly，manyplasunlight。Thelatskilledoffma-eatingdinosaurs，whicausedthedeathofthemeat-eatingdinosaursthatpreyedohedarkemperaturetofallbelpointformanymonths。Asaresultofthesuddenclimate，thedinosaurpopulationsbecamesmallerandsmaller。

&heoryadequatelyexplainswhydinosaursdiedout。PerhapsdinosaurssimplyotadjusttothegesthatlatheEarthtowardtheeaceousperiod。PerhapsitwasabinatiotributedtotheendoftheAgeofDinosaurs。

&wo

DoIt!

&omusiedoitquietly。Whilesomedoitintheprivacyoftheirowhersdoitingyms。Forsome，theydoitinthem，ht。Butnomatterwhereorwhen，millionsofpeopleallovertheworlddoit-andthatisaerobicexercise。Thebesularaerobicexercisearegreatbecauseithelppeopleimprovethefunsoftheirheart＆luboioress。

Probablythemostimmediateeffectofaerobicsisimprovedheartandlungfuns。ersonexergaheheartpumpsfasterandbloodiscirculatedwellthroughoutthebody。Siisamuscle，exerciseservestthenit。Astheheartbeesstronger，aperson'sstaminaimprovesaswellashisehesameistrueofthelungs。Apersoiveresultswithibywalkingbrisklyfor30mihreeorfourtimesaweek。

Thesedphysiefitularaerobicexercisetakesalittlebitlooachieve，butiswellworththeeffort，partien。Exerhelppreventthegboioeoporosis（骨质疏松症）。Osteoporosisisagradualprocessofbohatoaturallyaspeoplegrowolder，butitbehaltedbyregularaerobicexercise。Exerciseactuallyhelpsinass，andissaidtobethebestpreveoavoidosteoporosis。

Oiveeffectaboutaerobicexerciseisthatithelpsapersoress。Forexample，aerobicexermakeapersonfeelmorerelaxed，soheiscapableofhandlingdifficulties。Thatis，ersonexercises，hisbloodprovesandheburnsofftheadrenalin（肾上腺素）thatstresscausesthebodytoproduce。Also，exerhelpapersoridofhisstressaftersuffitaerobicexercise，becausehisbodyproducesbeta-endorphins，whiaturalstress-relievingchemicals。

Tosummarize，aerobicexereethodtomakeapersohinweeks。Sinceaerobicexercisedoesnotrequiremuchtimeoreffort，everybodyshouldgetenoughexersteadofwatgtelevisionsomue，apersoeroffwalking。

'sreadaalysisessaywrittenbyaesestudent。

WhyIEnjoyTravel

&likeamagicwater-color-brush，paintsmylifecolorfulandjoyful。WhenIfirststeppedoutofthecitywhereIwasbrewup，Iimmediatelylovedthefeeliingintouchwiththeoutsideworld。Sihen，Ihaveallaingtrips。Ienj，forityperspectives，developmyindependendimprovemyhealth。

First，travelisaivewaytoenriowledge。Iiesandtries，theculturesandsvarygreatly。Forexample，acowisahollyanimaltoIndia；Seoionalholidays。Ihavebeeiesinparativelyspeaking，althoughpeopleallspeakese，theirdialectsdifferfromeachother。Besides，peoplelivingiareasseemtodisplaydistiies。Thesoutherobegentleahenortherners，boldandstraightforward。Therefhmeetingle，Itheirdialederstaures，andgainnewknowledge。

&ravelprovidesmeortunitytobemoreself-reliaingoff，Ihavetomakeatravelplan，bookapla，makeahotelreservationainformationabouttheplaceIwillvisit。Allwillhavetobedonebymyself。Whiletraveliosolvetheproblemsthatmayoexpectedly。ThemomentswhenIlosemypurseorwhenIotgetaretur，Idonnobodybutmyself。Throughtheseseeminglytrivialexperieravel，Ihavebeoretihunforeseendiffilife。

Last，traveltributegreatlytomyhealthintwoways。Forohing，itiofexercisessuchasswimming，skating，gmountains，whiyhealth。F，siravelbringsfunandkeepsmeingoodmood，itreleasesmyworkpressureandhaspositiveeffeeh。Iravelbeallyandphysically。

Insummary，eamytrip，Iaewknowledge，improvemyabilityaermyhealthea，Ihopetomakemorejourneys。Meanwhile，Iwish，mydearfriends，youea'ssharethepleasuresfromtravel。

******

Towriteawell-anizedalysisessay，youshouldfollowtheguidelinesbelow。

1。Trytotrolyourprejudiyourcausalreasoning。Forexample，gthatthereasonwhyoneofyourclassmatesfailedhisfihathistea'tlikehimbeirresp。Youshouldeachersimplybecauseyouandyourclassmateareclosefriends。Instead，youshouldexploreallthepossiblereason（s）behindhisfailure。Withoutathoughtfulandthhanalysis，yesuperfidoasituatioooquivestigateyouroeciallywhehyourownproblemsorbeliefs。

2。Avoidoversimplifiwritingaalysisessay。Tople，that“ourpla'spollutionproblemscouldbesolvedifweallrecycled”isastatementwhiplifiesaplexissue。Mostplexissueshavemorethanonecauseoreffeakeyouranalysisaspleteaspossible。

3。Limityouressaytoadisostimmediate，mostimportantfactors。Asituatiomayhaveseveralcausesoreffects；however，youdoodisinorcausesoreffeapproximately300-wordessay。Insomecases，youdisoteorminorcausesoreffects，butdosoreasonably。Carefullyseleaterialbeagreatassetwheingaalysisessay。

4。Arrangeyourdisofcausesoreffectsagtooonpriheimmediatetotheremote，fromthelocaltothenational，fromtheobvioustothesubtle，fromthecriticaltothelesssignifiajortotheminor，fromthemostimportaimportac。。Ofcourse，youalseyourdistheotherwayrouionsareyoushouldpresentyourdistheorderthatmostdeffectivelypresentsyourideas。

Practice5-3-1

Lookatthelistofitemsbelow。Theitemsiaybecausesoreffectsoftheitemsiemsaremixedup。

1）jogging

a）heavyrainandstrongwinds

2）brokenhome