IfyouaskmewhatthelittleanimalsIlike,thenI'lltellyouthatthelittleanimalIlikeisthepuppy.
Mydog'shairissnowwhite,likesnowfallingonthedoglike,prettyverybeautiful!Apairofeyeswatery,asifjustunderaspringrain,rainfellintohiseyeslike;Longtail,ifthedustonthestreet,youcanusethetailtosweepthedustclean.
OnceIcamehomefromschool,Iwenttoseethepuppy.Ibiteittoeatit,butitnotonlydoesnoteat,butalsomotionless,asifwhatwasannoying.Theoriginal,thedogwillhaveababy......
Babyisborn,Ilovethedogmore.Butdidnotlastlong,theunfortunatethinghappened.Oneday,thedogsquattinginthemother'sparkingposition,whenmymothercameback,mymothercouldnotsee,thedogfellasleep,donotknow.Atthistime,mymotherparkedinthatposition.Atthistime,thedogwaskilledbyhermother.Seethisscene,Iwassad,continuouscryfor2hours.
Atthistime,myfeelingsaboutthedogisstillsodeep,Ifeelreluctanttolovethedog'sdeath.Puppyiloveyou.
Iliketheanimalsverymuch,butmyfavoriteanimalismyunclepickedupthepuppy.
Thepuppy'shairisyellow,hisearspointed,hishigh,hiseyesroundandbig,blackandbright,hisnoseblackandupright,itsmouthissmall,Itstaillongswingtoswing,verycute.
Puppyeatingfoodwhenverycute,Iputtheribsintoasmallbowlinside,hefartosee,allofasuddenranover,firstwithasmellofthenose,itsmelledthetasteofribs,immediatelydangling,Bigmouthtoeatup.Puppyhabitseverytimetoseestrangethings,havetousethenosetosmell,whenitwilleatsomethingcrispsound.
Itisalwaysinfrontofhisforefootonthefront,backontheback,hesometimeswhenhewasgoingtosleepbarkingsound,asifinadream.
PuppyandIoftenplaythegameisrunning,itranlikeariverwhenthesameactionisveryagile.
Ireallylikethispuppy,shouldbe,ithasbeenwithmeagoodtime.
DoyouknowwhatkindofanimalIlikemost?It’smonkey.Monkeyisakindoflovelyanimal.Manypeoplelikemonkeysverymuch.Generally,monkeyhassmallbodycoveredwithfur.Somekindsofmonkeyshavetwobigeyesandearsandalongtail.IcanseethemonTVorthezoo.EverytimeIgotothezoo,Iwillgotoseethem.Monkeysoftenstayintreesandjumpbetweenthem.Theyaresolivelyandfavorable.Whentheyarehappy,theywillactforvisitors.It’sveryfunny.
Atriplebaconcheeseburgerseemslikeaheartattackonaplate.
三层奶酪咸肉汉堡感觉吃完很容易让人突发心脏病。
Sohowcanpolarbearsthriveontheirversion,sealblubber?
那么,北极熊是如何处理这些高热量食物的呢?
Turnsoutthey'vestockedupongenesthatletthemclearfatsfromtheirblood.
结果显示它们储存在遗传基因里的信息使得它们能够清除血脂。
That'saccordingtoastudyinthejournalCell.
这是根据《细胞》杂志上的一篇研究得出的结论。
Polarbearsarewelladaptedtolifeontheseaice.
北极熊非常适应在浮冰上的生活。
Uptohalftheirbodyweight'sfat,whichgivesthemextrainsulationandbuoyancy,andprovidesthemwithareadysourceofenergy.
几乎占它们身重一半的脂肪足以使它们保暖并且维持体力，提供给它们一种易转化的能量。
Buthowcanananimalsofatalsobesofit?
但一种动物怎么能又胖又健康?
Researcherscomparedthegenomesofpolarbearswiththoseofbrownbears,andfoundthatpolarbearshaveaccumulatedgeneticchangesthatboosttheirhearthealthandfatmetabolism.
研究人员们通过比较北极熊和棕熊的基因，发现北极熊的基因组中积累了不少有利于心脏健康和脂肪代谢的.遗传突变。
Onegeneinparticular,calledApoB,helpsmovecholesteroloutoftheblood—whereitcausesproblemsinhumans—andintocells.
特别是编码为载脂蛋白B的基因有助于清除血液中对人类有害的胆固醇转变成细胞代谢。
Thesegenomicchangeshappenedquickly,evolutionarilyspeaking.
这些遗传变化从进化的角度来讲发生的十分快。
Polarbearsandbrownbearsdivergedfromacommonancestorlessthanhalfamillionyearsago.
北极熊和棕熊都来自于同一个祖先，它们是在大约50万年前左右开始向不同分支进化。
Butifthatseemssuperspeedy,theabilitytodigestlactosedidn'tspreadthroughhumanpopulationsuntilwedomesticatedcows,just10,000yearsago.
但是如果这种变化看上去十分快速的话，消化乳糖的酶逐渐进化到人类各个种群中也还是发生在大概1万年前我们可以驯化乳牛之后。
Amooovingtestamenttothepowerofnaturalselection.
这是自然选择力量的证明。