介绍猎豹的英语作文80词

Thecheetah'schestisdeepanditswaistisnarrow.Thecoarse,shortfurofthecheetahistanwithroundblackspotsmeasuringfrom2to3cm(0.79to1.2in)across,affordingitsomecamouflagewhilehunting.Therearenospotsonitswhiteunderside,butthetailhasspots,whichmergetoformfourtosixdarkringsattheend.Thetailusuallyendsinabushywhitetuft.Thecheetahhasasmallheadwithhigh-seteyes.Blacktearmarksrunfromthecornerofitseyesdownthesidesofthenosetoitsmouthtokeepsunlightoutofitseyesandtoaidinhuntingandseeinglongdistances.Theadultcheetahweighsfrom40to65kg(88to140lb).Itstotalbodylengthisfrom115to135cm(45to53in),whilethetailcanmeasureupto84cm(33in)inlength.Malestendtobeslightlylargerthanfemalesandhaveslightlybiggerheads,butthereisnotagreatvariationincheetahsizesanditisdifficulttotellmalesandfemalesapartbyappearancealone.Comparedtoasimilarly-sizedleopard,thecheetahisgenerallyshorter-bodied,butislongertailedandtaller(itaveragesabout90cm(35in)tall)andsoitappearsmorestreamlined.Somecheetahsalsohaveararefurpatternmutation:cheetahswithlarger,blotchy,mergedspotsareknownas'kingcheetahs'.Itwasoncethoughttobeaseparatesubspecies,butitismerelyamutationoftheAfricancheetah.The'kingcheetah'hasonlybeenseeninthewildahandfuloftimes,butithasbeenbredincaptivity.Thecheetah'spawshavesemi-retractableclaws[6](knownonlyinthreeothercatspecies-theFishingCat,theFlat-headedCatandtheIriomoteCat)offeringthecatextragripinitshigh-speedpursuits.Theligamentstructureofthecheetah'sclawsisthesameasthoseofothercats;itsimplylacksthesheathofskinandfurpresentinothervarieties,andthereforetheclawsarealwaysvisible,withtheexceptionofthedewclaw.Thedewclawitselfismuchshorterandstraighterthanothercats.Adaptationsthatenablethecheetahtorunasfastasitdoesincludelargenostrilsthatallowforincreasedoxygenintake,andanenlargedheartandlungsthatworktogethertocirculateoxygenefficiently.Duringatypicalchaseitsrespiratoryrateincreasesfrom60to150breathsperminute.[6]Whilerunning,inadditiontohavinggoodtractionduetoitssemi-retractableclaws,thecheetahusesitstailasarudder-likemeansofsteeringtoallowittomakesharpturns,necessarytooutflankpreywhooftenmakesuchturnstoescape.Unliketruebigcats,thecheetahcanpurrasitinhales,butcannotroar.Bycontrast,thebigcatscanroarbutcannotpurr,exceptwhileexhaling.However,thecheetahisstillconsideredbysometobethesmallestofthebigcats.Whileitisoftenmistakenfortheleopard,thecheetahdoeshavedistinguishingfeatures,suchastheaforementionedlongtear-streaklinesthatrunfromthecornersofitseyestoitsmouth.Thebodyframeofthecheetahisalsoverydifferentfromthatoftheleopard,mostnotablysoinitsthinnerandlongertail,andunliketheleopard,itsspotsarenotarrangedintorosettes.Thecheetahisavulnerablespecies.Outofallthebigcats,itistheleastabletoadapttonewenvironments.Ithasalwaysproveddifficulttobreedincaptivity,althoughrecentlyafewzooshavemanagedtosucceedatthis.Oncewidelyhuntedforitsfur,thecheetahnowsuffersmorefromthelossofbothhabitatandprey.Thecheetahwasformerlyconsideredtobeparticularlyprimitiveamongthecatsandtohaveevolvedapproximately18millionyearsago.Newresearch,however,suggeststhatthelastcommonancestorofall40existingspeciesoffelineslivedmorerecentlythanthat-about11millionyearsago.Thesameresearchindicatesthatthecheetah,whilehighlyderivedmorphologically,isnotofparticularlyancientlineage,havingseparatedfromitsclosestlivingrelatives(Pumaconcolor,thecougar,andPumayaguarondi,thejaguarundi)aroundfivemillionyearsago.[7][8]Thesefelidshaven'tchangedmuchsincetheyfirstappearedinthefossilrecord.