高中英语完形填空命题规律探寻与练习（含答案）

【培优讲义】高中英语完形填空命题规律探寻与练习

完形填空总的原则：“先完意，后完形”。

整体的经验模式：整体结构一组成部分

【命题特点】：长度一般250词左右体裁以记叙文为主，夹叙夹议题材广泛。结构紧凑，层次分明，逻辑性强。实

词为主，虚词为辅。命题原则“强调应用，注重实际”。首句通常不挖空。答案分布均匀，词汇语境化。

【解读策略】

1.通读全文，理解大意。重视首句信息，跳过空格，浏览全文，感知全文，理解文章大意，这是解题的基础。

2.瞻前顾后，避难就易。在理解文章大意的情况下，结合各选项的意义和用法，遵循先易后难的原则，先解决那

些自己有把握的问题。对少数难题，暂时跳过，或许在上文中难以判断的题在下文中就有暗示或者明显的提示，或

许一个在前面不能解答的题在填出了另一空后会令你豁然开朗。

3.复读全文，解决残敌。借助已经补全的空格，我们对全文有了更清楚的理解，可以集中解决遗留的疑难问题。

4.再次复读，弥补疏漏。全部做好后，考生务必要结合自己选择的答案重新阅读短文内容,确保全文文意连贯。

词汇方面突出的变化有两个方面。一是“大词”的考查，以前在阅读理解中出现的高频词，如spritual,abruptly,

advocate,consequence,metaphorical,temporarily,constantly等词汇也出现在完形中，加大了试题难度。二是“熟词生

义”的考查，近两年完形中都会出现2-3个“熟词生义”的词汇，这往往是影响学生理解的地方和失分的原因。

【备考提示】

分析文本，整体把握文章结构和思路。文章讲述的是一件什么事？表达一个什么样的观点？从哪几个角度表达

该观点？传递一种什么价值观？

重视长难句分析。通过分析句子结构，提高学生对文本和长难句的理解力。

利用阅读语篇复习词汇、句型。尤其重视词汇使用的语境，提高学生对词汇的准确理解力。此外，也加强对词

源义的了解，积累“熟词生义”，提高学生猜词能力。

限时训练，文章反复做，设置更多的空。第一次处理完文本后，可挖出更多的空，删去选项进行练习，即进行

无答案填空形式的训练，提高学生准确运用词汇的能力，增强其对语境的准确理解。

解题步骤规范化。强调答题前2分钟时间浏览全文，了解语篇大意---who,what,when,where&how,推断文章

主题；利用前后线索，谨慎答题。

【解题步骤】

1.首句得信息，分析主结构

ThefirsttimeIsawher,shelookedmessyandtired.She1thatshewasinbadluckandcomplainedabouther

2lifeallthetime.Listeningtoher,Ifeltlikedoingsomethingtohelp.

1.A.screamedB.announcedC.insistedD.whispered

2.A.colorfulB.adventurousC.extraordinaryD.misfortunate

Ithasbeenarguedbysomethatgiftedchildrenshouldbegroupedinspecialclasses.The_1_isbasedonthebelief

thatinregularclassesthesechildrenareheldbackintheirintellectual（智力的）growthby_2_situationthathasdesigned

forthe_3_children.

1.A.principleB.theoryC.argumentD.classification

2.A.designingB.groupingC.learningD.living

3.A.smartB.curiousC.matureD.average

2.注意逻辑性,语气成提示

Hehadspentthoseyearswell,graduatingfromcollege,completingtwointernships（实习）inWashington,D.C,and.

becomingatechnicalassistantinSacramento.

A.hopefullyB.finallyC.particularlyD.certainly

Firstofall,Irespectedhisdevotiontoteaching...___43___,Iadmiredthefactthathewouldtalktostudentsoutsidethe

classroomortalk...Finally,Iwasattractedbyhislivelysenseofhumor.

43.ALaterB.SecondlyC.howeverD.Therefore

Oncehe___42___sangasonginclassinordertomakeapointclear.

42.A.alsoB.nearlyC.evenD.only

3.同词复现，灵活填词

重视语境：完形填空并非完成单独的词汇或句子练习，需在语篇中根据上下文语境做出正确判断。

综合运用：任何技巧不会独立存在，在实际运用中往往多个技巧结合使用。

重视积累：任何技巧的使用脱离不了扎实的语言基础知识，需在学习中不断积累。

Ibegantotakerisks.Ihadbeensoafraidoffailing...Shetaughtmetotakechancesandnotbe.

A.boredB.lazyC.sadD.afraid

Yearslater,whenIstoodinthekitchenofmynewhouse,thinkinghowIwantedtomakemyChristmasthere

specialandmemorable...

A.presentB.firstC.recentD.previous

_39_ashighashecould,butevenathistallest_40_hewasunabletotouchit....atthetopofeachjumpstretchinghis

armsto...

39.A.expandingB.stretchingC.swingingD.pulling

40.A.strengthB.lengthC.rangeD.height

Iputmyheadin,expectingtheworst.Buttomysurprise,theroomwasn'temptyatall.Ithadfurniture,curtains,aTV,

andevenpaintingsonthewall.Andthenonthewell-madebedsatAmy,mynew,dressedneatly.

A.roommateB.classmateC.neighborD.companion

4.固定搭配，注重积累

TellinghimthathenolongerneededtoenjoythembutIstillneededtowritethem,Iuntilthedayhegraduated.

A.heldupB.gaveupC.followedD.continued

5.推理能力培养

Mrs.Blackwouldaskmeformy___.ShewantedtoknowhowIthoughtweshouldthings.AtfirstIhadnoidea

howtoanswerbecauseIknow___aboutstagedesign!

2.A.opinionB.impressionC.informationD.intention

4.A.anythingB.somethingC.nothingD.everything

Hewasreadingmywordsoutloudtotheclass...thewholeclasswaslaughingwithopen-heartedenjoyment.Ididmy

bestnottoshow___53___,butwhatIwasfeelingwaspurehappiness...

53.A.shockB.wonderC.worryD.pleasure

6.文化背景，常识解题

（北京卷）Butwerunsomuchthat,afterwards,wehadtrouble___45___.

A.speakingB.movingC.sleepingD.breathing

（山东卷）WhentheydiscoveredthatBlackWednesdayweregoingtoperformatourlocaltheatre,theyallbought

—38—forperformance.

38.A.flowersB.drinksC.clothesD.tickets

AftertheBritishflagatthePole,theytookaphotographofthemselvesbeforetheystartedthe950-milejourney

back.

A.GrowingB.puttingC.plantingD.laying

Yesterdaythesalesofficerangustosaythecarwas.

A.rightB.readyC.fixedD.sold

7.巧用排除，解决壁垒

巧用排除方法，缩小选择范围

解答完形填空题需要考生进行认真的阅读、理解、推理和判断，需要对4个选项进行仔细的辨别、分析，从而

去伪存真。有时我们会遇到这样的情况，对某个题目的正确选项的含义、用法不甚明白，

但发现其他选项有显而易见的谬误。这时，我们可以尝试着用排除法。所谓排除法就是将干扰项逐项检查、验证

,发现错误的选项立即剔除。随着选择范围的缩小，选中正确选项的几率逐渐增大。排除法如果运用得好，可以

大大节省时间和精力。

（四川卷）Somedayslater,Iwastoldthataguywhowasworkingwithusthatday,"couldprobablyhavemadeafortune

_24_thenecklacehefound.

24.A.hidingB.stealingC.sellingD.wearing

Heputthebooksintothereturnbox.Andafterabriefinthetoilet,hewouldbeonhiswaytotheplaygroundto

meetEric.

A.restB.breakC.walkD.stop

练习部分

【真题体验】

【2021.1浙江卷】

LastyearIdecidedtodosomevolunteerwork.Ibeganto36ontheInternetanddiscoveredVolunteerUSA.Three

monthslaterI37myselfonaplanetoPhoenix,Arizona.Iwas38atthethoughtoflivingwithloadsofnewpeople

fbrthreemonths.However,withinfifteenminutesof39-myworrieshadgone.Everyonewasso40and

like-mindedthatitwasvery41tofeelathome.

IwassenttotheCoronadoNationalForestformyfirst8-day42.Wehadto43everythingweneededandwalk

threemilestowhereweworked.Itmaynotseemlikea44waybutin35℃heatandwithaheavypack,mylegswereon

fire.

Myjobwasto45astairwayoutofrock.This46climbingupanddownthesideofamountaininhabited（栖

息）bymountainlions,althoughIshouldsaytheywereonlyheard,never47.

Threedayslater,abeautifulstairwaycameintobeing.The48ofknowingthatmy49willbeonthat

mountainsideforyearstocomeismassive.

Butonthelastnightwewere50inathunderstorm.Iwokeupatmidnighttofindaswimmingpoolinmytent.The

temperaturewascloseto51.1hadtospendtherestofthenighttremblingintheonly52partofmytent.

53_,Isufferedalot.ButIknowwhateverIhavetofaceinmylifeIwasthereandI54.1thinkIam

much55forhavingtakenpartintheproject.

36.A.calculateB.negotiateC.advertiseD.research

37.A.imaginedB.introducedC.enjoyedD.found

38.A.annoyedB.surprisedC.scaredD.excited

39.A.arrivingB.sleepingC.thinkingD.walking

40.A.confidentB.friendlyC.energeticD.curious

41.A.funnyB.goodC.luckyD.easy

42.A.tourB.projectC.campaignD.course

43.A.dropB.makeC.carryD.buy

44.A.niceB.safeC.longD.quick

45.A.buildB.testC.cleanD.guard

46.A.helpedB.endedC.allowedD.meant

47.A.huntedB.trainedC.seenD.fed

48.A.satisfactionB.ambitionC.expectationD.intention

49.A.workB.memoryC.recordD.story

50.A.leftB.caughtC.attackedD.separated

51.A.boilingB.averageC.normalD.freezing

52.A.tidyB.dryC.newD.soft

53.A.BythewayB.RegardlessofthatC.NeedlesstosayD.Ineithercase

54.A.survivedB.resistedC.escapedD.recovered

55.A.smarterB.strongerC.happierD.busier

【解析】本文讲述作者参与志愿者活动，其过程是艰苦的、惊险的，但收获是巨大的。

【2020新全国2卷】

WhenJimGrantspottedblacksmokecomingoutofabuildingonhiswaytowork,he41hiscartocall911.

Thenhe42aU-turn,circlingbacktotakeanotherlook.

Pullinguptothebuilding,Grantsawflames(火焰)shootingoutofasecond-floorwindow.Notseeingorhearingany

fireengines43Grantrushedtoaside44andranupthestairs.

Onthesecondfloor,he45everyapartmentdoor."Getout!"Grantshouted,Noone46andheassumedthat

peoplehadalready47Reachingtheendofthehallway,though,Grant48ahalf-opendoor.Hekickeditwide

open,findinga49womaninawheelchairwithalittleboyandatinybaby."Let's50!"hescreamed.The

womanlookedathiminconfusionandsaidsomethingaboutchangingherclothes.Grantdidn'twait,Clutching(抓牢)the

babytohischestand51theboyalongside,Grantrandownthehallway.Whenhewas52outside,theonly

53insightwasapoliceman.Granttoldhimaboutthe54andtheyrushedintothesmokybuilding.

Thankstothem,afamilywassavedfromthefire.Grantandthepolicemanwerehonoredfortheir55

()41.A.droveB.stoppedC.reachedD.abandoned

()42.A.sawB.madeC.missedD.crossed

()43.A.burningB.leavingC.approachingD.waiting

()44.A.entranceB.roadC.buildingD.window

()45.A.lockedB.kickedC.countedD.repaired

()46.A.agreedB.caredC.respondedD.understood

()47.A.arrivedB.returnedC.hiddenD.escaped

()48.A.skippedB.closedC.noticedD.remembered

()49.A.frightenedB.curiousC.patientD.grateful

()50.A.turnbackB.goupC.getoutD.liedown

()51.A.followingB.draggingC.examiningD.passing

()52.A.safelyB.secretlyC.suddenlyD.previously

()53.A.witnessB.guideC.serviceD.help

()54.A.womanB.doorC.carD.baby

()55.A.wisdomB.generosityC.honestyD.courage

【经典浙江卷】

AlthoughIlovemylife,ithasn'tbeenalotoffirnasFvebeenillfor28years.

Musichasalwaysbeenagreatloveofmineand,inmy20s,whenmy21wasmoremanageable,I22ten

yearsasaprofessionalsingerinrestaurants,playingandsingingfolksongs.23thatwasyearsagoandtimeshave

changed.24Ilivewithmotheronacountryfarm.

Twoyearsago,IdecidedthatIwouldneedtohavesomekindofextraworkto25mydisabilitypension（残疾抚

恤金）.26Ineededtosleepintheafternoons,Iwaslimitedinmy27.1decidedthatIwouldconsider28

tosinginginrestaurants.

Myfamilyareallmusicians,soIwas29whenIwentintoourlocalmusicstore.IexplainedthatIwantedtosing

againbutusingrecordedkaraokemusic.IknewthatdiscswereveryexpensiveandIreallydidn'thavealotof30to

getstarted.And31youfindonlythreetofoursongsoutoftenonadiscthatyoucan32use.

WhenItoldtheowneroftheshopaboutmy33;hegavemealongthoughtful34."Thismeansalotto

you,doesn'tit?"hesaid."Comewithme.”

Heledme35thecrowdedshopandtoabenchwithalargeprofessionalkaraokeboxonit.Heplacedhislarge

hand36onhistreasureandsaid,“Ihave800karaokesongsinhere.Youcantakeyour37andI'llrecordthemfor

you.Thatshouldgetyoustarted.9,

I38.Thankinghim,Imadeatimewithhimtolistentoallthesongsandchoose39thatIcouldsing.Ihave

comefullcirclewithhishelp.

His40stillwarmsmyheartandmakesmedojustthatbitextra,whenIhavethechance.

21.A.lonelinessB.sadnessC.tirednessD.sickness

22.A.setB.enjoyedC.keptD.shared

23.A.GladlyB.EventuallyC.UnfortunatelyD.Surprisingly

24.A.NowB.ThenC.SometimeD.Meanwhile

25.A.adduptoB.makeupforC.getridofD.takeadvantageof

26.A.IfB.AsC.ThoughD.Before

27.A.movementB.conditionC.choicesD.positions

28.A.reachingoutB.livingupC.gettingonD.goingback

29.A.recognizedB.interviewedC.foundD.invited

30.A.moneyB.timeC.energyD.knowledge

31.A.thusB.onceC.seldomD.often

32.A.actuallyB.hardlyC.nearlyD.formerly

33.A.jobB.familyC.ideaD.offer

34.A.faceB.viewC.lookD.sight

35.A.overB.alongC.towardsD.through

36.A.unhappilyB.lovinglyC.pitifullyD.gratefully

37.A.pickB.turnC.roleD.step

38.A.hadtocryB.oughttocryC.shouldhavecriedD.couldhavecried

39.A.moreB.theonesC.fewD.therest

40.A.courageB.devotionC.kindnessD.trust

【基础特训练满分】

①【杭州七县联考】

Wecan'tpredictthefuture,butallweknowforsureisthatlifewillneverbethesame.

Ihadalwaysbeen36abouttraveling,andinour8yearstogether,wemadefulluseofour37budgetand

time,travelingasoftenaswecouldnearorfar,evencheckingHawaiioffthebucketlist

38、oncemyhusbandwasdiagnosedwithstage4cancer.Ididn'tgobackto39atallforoverayear.For

6months,mylifebecameaboutbeingthecaretaker,personaldoctorandwifeIcouldpossiblybe.Ilivedand40for

himbecausethafswhathedeservedandneeded,andIwantedtospendeverysecondIhad41withhim.

Sadly,hewasgone.Iwas42.Atthattime,afamilymember43theirapartmentinHawaiitomeifI

wantedtotakesome44formyself.IknewthiswaswhatIneededtodo.ArrivinginHawaiibymyselfwasquite

possiblythe45feelingever,secondonlytoleavingthehospitalthedayhe46.ButIrentedacar,Iwalkedthe

beach,Ihikedtowaterfalls,andIspenttimewitholdfriendswholivedthere.47.1learnedIwasmyowngoodfriend

andIcould48myself..Beingalonewithmythoughtsand49wasthehardestthingIcould50.butI

thinkatthetime,itseemed51thangoingbacktomyoldroutinewithahugevacancyinmylife.

Andprettysoon,Iwasonthego52.Afternumeroustrips,Ifeltitwastimetoreturntowork.Istartedtolivelife

tothe53experiencingthingsIwouldneverhaveimagined.

.NowIdon'twanttowaitto54mydreamsandcheckthingsoffmybucketlist.Ihopeyoudon't55.

36.A.crazyB.concernedC.anxiousD.worried

37.A.limitedB.equalC.enoughD.proper

38.A.AnywayB.BesidesC.HoweverD.Therefore

39.A.hospitalB.schoolC.exerciseD.work

40.A.criedB.smiledC.shoutedD.breathed

41.A.enjoyedB.leftC.takenD.wasted

42.A.inamazementB.inshockC.atalossD.atrisk

43.A.receivedB.offeredC.soldD.sent

44.A.moneyB.adviceC.energyD.time

45.A.happiestB.loneliestC.mostawkwardD.mostembarrassing

46.A.diedB.recoveredC.passedD.returned

47.A.ActuallyB.ObviouslyC.GraduallyD.Generally

48.A.dependonB.checkonC.reflectonD.focuson

49.A.commentsB.admirationC.surpriseD.memories

50.A.forgetB.hopeC.faceD.identify

51.A.harderB.easierC.worseD.safer

52.A.continuouslyB.anxiouslyC.safelyD.powerfully

53.A.leastB.fullestC.busiestD.simplest

54.A.leaveB.establishC.followD.survive

55.A.tooB.yetC.neitherD.either

②【宁波九校联考】

AsIlayhereinmyhard36hospitalbed,nobodycouldunderstandhow37Iwantedto

leavethisplace.I38mymomtograbmemykeys.Onmykeychain,therewasasoftpieceofleather.She

gavemea（n）39lookasifshethoughtIwasgoingtodrivemyselfhome,butactuallyIjustwantedto

40theonlythingthatsymbolizedmytruepassionand41somanymemoriesthattransformed

measaperson.

EverytimeI42theleatherIwouldthinkofonething-43.Theleatherwasmadeofmyfirst

baseballglovethatI44somuch.Lyinginmybedwithmyeyes45,Iwastakentoasports

field.Thefreshlycutoutfieldgrasswaslusciousgreen.Thebaselinesweregleamingwhiteandperfectlystraight.Iheard

a46ofthejudgesspeakingwiththecoachesandtheparentschattering（闲®P）・Myteammates*cleats（防滑

钉）were47astheywalkedacrossthedugout（球员席）anxiously48thechampionship

game.Withayellof"PLAYBALL"，Ibeganatrot（小跑）outtomyhomeatfirstbaseandeverything49

smoothly.

50,mynursewalkedinandIjumpedwhenIheardhervoice.Shedidn'tmeanto51me,but

Ineededsomemedicineandshouldgetexamined.52myeyesopen,theroadtripthatIwasoninmybrain

wasnowover.Iwasbacktothe53ofmedicaldevicesandaswollenarm.Irealizedanhourhadpassed!Even

in54times,thethingsandpeopleyoulovedcouldhelpyouescapeandevenyour55.

36.A.suitableB.awkwardC.amazingD.uncomfortable

37.A.obviouslyB.badlyC.actuallyD.immediately

38.A.threatenedB.beggedC.demandedD.suggested

39.A.annoyedB.delightedC.confusedD・relieved

40.A.removeB.packC.holdD.determine

41.A.carriedB.deliveredC・contributedD・established

42.A.exploredB.searchedC.gainedD.felt

43.A.baseballB.gloveC.fieldD.grass

44.A.reservedB.valuedC.stressedD.recommended

45.A.shutB.closeC.narrowedD.open

46.A.soundB.mixC.noiseD・conversation

47.A.strikingB.crashingC.attackingD・clicking

48.A.admiringB.expectingC.playingD.applying

49.A.gotB.turnedC.wentD・appeared

50.A.AllofasuddenB.IntheendC.OnceinawhileD・Onceuponatime

51.A.requireB.confirmC.checkD.interrupt

52.A.WithB.OnC.DespiteD.At

53.A.challengeB.trackC・realityD.system

54.A.specificB.uniqueC.curiousD・tough

55.A.hourB.momentC.dayD・time

③

YesterdayafternoonIwasinmystudioworking.Iwaschattingonthephonewhensomethingmademe36.Outofthe

window,ontheothersideofthestreet,Isawmyveryelderlyneighborkneeling（跪下）inthegrass,his37besidehim.nPve

gottogo,"Isaidtomyfriend,thinksomethingiswrong.9,SoI38downstairs,outmyfrontdoorand39thestreet.

"Hewastakinga40,andhetripped（绊倒）onthepavement/9thecaregiversaid.HIcan't41himonmyown.^^My

neighborisa42man,soIranbackhomeandgotmyhusband!Togetherwewereabletogethim43,buthecouldn9twalk.

44,awomanbicycledbyandaskedifweneeded45IShegotalawnchairfrommyfrontporchandwegotmyneighbor

46.Afterrestingforafew47.wewereabletohelphim48thehouse.HIdon'tknowwhatIwouldhavedone49youhadn9t

rushedovertohelp.Iwasall50hiscaregiversaid.

Sohere*swhatI'vebeen51sinceyesterdayafternoon:Helpyour52.Lookupfromwhatyouaredoing,andlook

aroundforwhoyoucanhelp.Itmaynotbeas53asitwasinthiscase,butthere'salwayshelpyoucan54.Youcangive

helptoyourneighboracrossthestreet,orthepersonstandingbesideyou.Theyareallyourneighbors.Your55willbe

appreciated.

36.A.lookdownB.lookbackC.lookupD.lookon

37.A.caregiverB.adviserC.assistantD.wife

38.A.climbedB.slidC.jumpedD.ran

39.A.overB.acrossC.alongD.through

40.A.rideB.walkC.busD.taxi

41.A.catchB.comfortC.liftD.push

42.A.greatB.largeC.weakD.slim

43.A.standingB.speakingC.lyingD■jogging

44.A.StrangelyB.LuckilyC.SurprisinglyD.Hopefully

45.A.helpB.careC.exerciseD.credit

46.A.protectedB.changedC.seatedD.tracked

47.A.hoursB.secondsC.minutesD.days

48.A.breakintoB.slipintoC.checkintoD.getinto

49.A.unlessB.untilC.thoughD.if

50.A.aloneB.amazedC.awakeD.annoyed

51.A.arguingaboutB.thinkingaboutC.complainingaboutD.talkingabout

52.A.neighborB.customerC.friendD.relative

53.A.obviousB.importantC.formalD.powerful

54.A.seekB.receiveC.recommendD.offer

55.A.honestyB.wisdomC.kindnessD.responsibility

【拓展延伸练水平】

①

ThishappenedwhenIwasten.OnanormalSunday,IwenttothebarbershopwhereIalwayswent.Thatday,alongwith

thebarbertherewasanassistant,whohadrecently41theshop.

SoIsatfbrthehaircut.Theuncleaskedmehow42Iwantedit.Ianswered,HJustdoasmydadhad43youthelast

Hesmiled.Beforestartingthe44，headded,6tWhatifIkeepitlong?"

145hewasjoking.SoIjokedtoo.Isaid,Tcan't46whatwouldhappentoyourshopthen!"

ThemomentIsaidit,theassistant47frombehind.4tHowdaredoyousaythat!Whoareyoutotakeusdown,eh?”

IadmitIwastoo48atthatmomentandtheunclestandingbesidemewasgivingmean49look.

Fromthatdayon,I50stoppedjokingaboutanyonesprofessionandworks.Itisoneofthemost51incidentsinmylife,

whichtaughtmeto52theprofessionandworksofaperson,nomatterhow53theyare.

fm54thattheassistantrespondedinawaythatmademerethinkthepowerofmywords.Wordsdomakea55.

41.A.leftB.openedC.joinedD.visited

42.A.muchB.longC.oftenD.soon

43.A.instructedB.invitedC.promisedD.convinced

44.A.discussionB.journeyC.trainingD.haircut

45.A.agreedB.heardC.hopedD.knew

46.A.forgetB.tolerateC.guaranteeD.understand

47.A.urgedB.shoutedC.laughedD.helped

48.A.angryB.proudC.scaredD.curious

49.A.anxiousB.appealingC.encouragingD.awkward

50.A.suddenlyB.completelyC.temporarilyD.regularly

51.A.importantB.excitingC.strangeD.interesting

52.A.learnB.enterC.changeD.respect

53.A.hardB.smallC.goodD.complex

54.A.sorryB.confidentC.gratefulD.embarrassed

55.A.differenceB.mistakeC.choiceD.joke

②

Inmystudyarecollectionsoftoys,abaseballbatandglovesofmychildhood.36fromoneshelftomyleftis

myfat