四川省内江市球溪中学2024届七下英语期末综合测试试题含答案

四川省内江市球溪中学2024届七下英语期末综合测试试题满分120分，时间90分钟一、单项选择（共10小题，满分20分）1、Afterfinishinghishomework,Tonyeitherplayschess________takesawalk.A.so B.or C.that D.if2、—Excuseme,istherealibrarynearhere?—________ButyoucanfindoneonChaoyangStreet.A.Yes,thereis. B.No,thereisn’t. C.Yes,therewas. D.No,therewasn’t.3、Itisrainingheavilynow.________,Itookanumbrella(雨伞).A.Easily B.Luckily C.Differently4、Iftheword“herself”isonpage958inadictionary,“hurry”onpage1002,“hole”maybeonpage_________.A.945 B.956 C.976 D.10075、—Suzy,what’s___________thebox?—Openit!It’sasurpriseforyou.A.beside B.outside C.behind D.inside6、Ourschoolshowis________6:00p.m.________Sunday.A.at;on B.on;in C.in;at7、Howdoyoureadthenumber"2547"?A.twothousandsfivehundredsandforty-seven B.twothousand,fivehundredandforty-sevenC.twothousands,fivehundreds,forty-seven D.twothousandandfivehundredandforty-seven8、Whichofthefollowing“-ed”hasadifferentpronunciation(发音)fromtheotherthree?A.looked B.followed C.rushed D.passed9、B【解析】【详解】句意：——坐公共汽车去火车站太晚了。——别担心，妈妈。我将乘出租车。考查副词的用法和形容词辨析。late“晚的”；early“早的”。enough“足够”修饰形容词，应后置，排除A、C；too“太”。根据“Don’tworry,Mum.Iwilltakeataxi.”可知，换乘了出租车，所以应是说乘公共汽车太晚了，故选B。10、Ihavetogotoschool________busonrainydays.A.at B.in C.of D.by二、完形填空（10分）11、阅读下面短文,从各小题所给的四个选项中选出最佳选项。Wemusthaveahealthybodyfirsttolivehappily.Healthisvery____1____.Ifwearehealthyandstrong,wecanstudyandworkwell.Ofcourse,wecanliveawonderfullife.Howdowestayingood____2____?Physical(身体的)exerciseisthebestway.Weshoulddosomeoutdoorsportsassoonaspossible.____3____thisway,wecangetclosertonatureandenjoyfreshair.Thebeautifulnaturewillkeepus____4____.Ilovesports.Ioftendophysicalexerciseto____5____mymindandbody.Iwouldfeelgoodevenafteraday’shardworkandwouldn’tgetill____6____.Ioftendosports,soIwon’t____7____weight.Buteverythinghastwo____8____.Sportsarethesame.Wemayhurt____9____peopleorourselvesbybeingnotcarefulenough.What’smore,toomuchtraining____10____doharm(伤害)toourhealth.Becarefulenough,andsportscandousnothingbutgood.1.A.comfortable B.boring C.worth D.important2.A.study B.health C.use D.practice3.A.In B.At C.To D.For4.A.sad B.happy C.sick D.rich5.A.reply B.reach C.relax D.research6.A.nervously B.easily C.luckily D.quickly7.A.puton B.putup C.workon D.workout8.A.sides B.ways C.degrees D.habits9.A.all B.any C.other D.another10.A.should B.can’t C.shouldn’t D.can三、完成句子（共5小题，满分10分）12、noodles,beef,has,lunch,for,he,often________________________________________________________________.13、朱迪总是能想出一些解决问题的好办法。Judycanalways________________________somegoodideasto________problems.14、It’seasyforme________(learn)Englishwell.15、Pleasecleanyourroombecauseit’stood________.16、别再吃快餐了。这类食物都是脂肪和盐。Don’teatfastfood________________.It’s________________________andsalt.四、阅读理解（40分）17、阅读下面短文，根据短文内容判断其后面所给句子的对错。选“对”涂A，选“错”涂B。I’mLeo.TodayisMonday.Myfriendsaretalkingabouthowtheyspenttheweekend.MaryIstayedathomeandstudiedalotattheweekend.IstudiedforthemathtestonSaturday.OnSundaymorning,IdidmyEnglishhomework.Intheevening,Italkedtomyfriendonthephone.Whatdidyoudo,Lucy?LucyIhadagreattime.Ivisitedmyfriends.OnSaturdayevening,wewenttoNancy’sbirthdayparty.Wesanganddancedattheparty.OnSundayafternoon,wewenttoanewparknearmyhome.Weplayedtennisinthepark.Andyou,Lily?LilyOh,yourweekendwasgreat!ButIhadaboringweekend.Istayedathomeanddidsomehousework.Icleanedmyroom.Ihelpedmymomcookdinnerandwashclothes.Tim,didyougoout?TimNo,Ididn’t.IstayedathomeandwatchedTV.YesterdayIwatchedamovie.Itwasveryinteresting.1.MaryvisitedherfriendsonSundayevening.2.Nancy’sbirthdaypartywasonSaturdayevening.3.Lilywenttothesupermarketattheweekend.4.Mary,LilyandTimstayedathomeattheweekend.5.Lucyhadfunwithherfriendsattheweekend.18、Once,therewasafarmerwhowasalwaysmean(刻薄的)tohiswife.Hetoldhiswifethatshewaslazyanddidn’tworkhardenough.Hethoughtshewasalwayswasting(浪费)hertimeathomewhilehewasworkinghardinthefield.Thewifegotsosadandwantedtoshowhimthathewaswrong.Sheaskedhimiftheycouldswap(交换)rolesforaday.Shewoulddothefieldworkandhewoulddothehousework.Thefarmeragreed,thinkingitwouldbeeasy.Butwhenthewifegavehimalistoftaskstodo,includingmilkingthecow,feedingthepigs,washingtheclothes,andtakingcareofthehen,thefarmerfoundoutthatitwasharderthanhethought.Hegotkicked(被踢)bythecow,hithisheadonthepigs’door,andforgottowashtheclothesandtakecareofthehen.Whenthewifecamebackfromthefield,shesawthathedidn’tfinishallofthetasks.Ontheotherhand,thewifedidtheworkinthefieldaswellashedid.Thefarmerfeltashamed.Heunderstoodthathewaswrongabouthiswife.Heshouldsaythankyouforherhardwork.Helearnedtorespect(尊重)herandneversaidmeanwordstoheragain.Fromthatdayon,theylivedhappilyeverafter.1.Thesadwifecameupwithanideaandshe________.A.neverdidthehouseworkagainB.hadafightwithherhusbandC.wenttoseeherhusband’sfieldworkD.playedeachother’sroleforaday2.AccordingtoParagraph2,thefarmer________thatday.A.couldn’tdoanytaskatallB.gotbadlyhurtmorethanonceC.livedafreeandcomfortablelifeD.missedworkinginthefield3.Theword“________”cantaketheplaceof“ashamed”inthelastparagraph.A.tired B.sorry C.angry D.excited4.Fromtheexperience,wecanlearnthat________.A.weshouldn’tlaughatothersanytimeB.itisn’trighttochangeourownjobsfreelyC.weneedtorespectothers’workinourlifeD.weshouldn’tsaymeanwordstobadpeople19、Heyeveryone!IamYangQiao.IliveinHongKong.IaminGrade4attheEducationUniversityofHongKongJockeyClubPrimarySchool.Atmyschool,therearemanyinterestingclassesandactivities.Letmeshowyoumydayatschool.MorningreadingWereadourtextbooks.IfitisMonday,weusuallyhaveaflag-raising.Wesingthenationalanthem（国歌）andourschoolsong.FirstclassMostofourclassesarelikeyours.WehaveChinese,mathandEnglisheveryday.Wealsohavemanyotherinterestingclasses.Oneofmyfavoritesiscomputerstudies.Ilearnprogrammingskillstomakesimpleonlinegamesorevenmusic.SecondclassAnotherclassIenjoyisgeneralstudies（常识课）.Thisclasscoversknowledgeofdifferentsubjects.Forexample,welearnChinesehistory.Wealsodosomefunscienceexperiments（实验）.ThirdclassFourthclassIthinkthemostdifficultclassisvisualarts（视觉艺术）.Wedon’tjustlearndrawing.Wealsolearnaboutarchitectureanddesign（建筑和设计）.Once,myclassmatesandIbuiltacity.Wefirstmadethedesignonacomputer.Then,eachstudentmadeabuildingwithcardboard.Together,ourbuildingsmadeupacolorfulcity.FifthclassLunchbreakcookingcompanysendsourlunchtoschool.Wehaveourlunchintheclassroom.Ilikecharsiu（叉烧）ricemost.Wecanalsobringhomemadelunchestoschool.1.WhatdothestudentsusuallydoonMondaymorning?A.Theyhaveaflag-raising. B.Theylearndrawing.C.Theymakeonlinegames. D.Theydoscienceexperiments.2.Whichclassisfrom9:50to10:4?A.Firstclass. B.Secondclass. C.Thirdclass. D.Fourthclass.3.Whatisthemostdifficultclassforthewriter?A.Morningreading. B.Math. C.Chinesehistory. D.Visualarts.4.Howlongdoesthelunchtimelast?A.Thirtyminutes. B.Fortyminutes.C.Forty-fiveminutes. D.Fifty-fiveminutes.20、LilyIenjoysunnyweather.Whenit’ssunny,Ifeelexcited.Icanrideabikeorgoforawalkwithmyfriends.Iwenttoazoowiththemlastweekend.Itwasexcellenttoseeanimalsonsunnydays.AndreDifferentfromLily,Ilikerainyweather.Itmakesmefeelrelaxedandforgetaboutsad(令人难过的)thingsinmyeverydaylife.Icanlistentomusicorwatchmyfavoritemovieathomeonrainydays.EmilIfeelsadwhenit’sraining.ButIlikesnow.Eachwinterinsnowyweather,Icanmakeasnowmanorgoskiing(滑雪).Lastwinter,myfamilytookatriptoHarbin.Itwasveryexciting.PaulIdon’tlikesnowyweatherbecauseit’stoocoldforme.SoIdon’tlikewinter.Ienjoysummer.It’sjustrightforswimminginthepoolorhavingapicnic(野餐)inthepark.1.Lilyfeelsgoodto________onsunnydays.A.rideabike B.goswimming C.listentomusic D.watchamovie2.Andrefeels________whenit’sraining.A.sad B.scared C.relaxed D.excited3.Itmight(可能)be________whenEmily’sfamilywenttoHarbin.A.rainy B.snowy C.cool D.warn4.Whoenjoyshavingapicnicinsummer?A.Andre. B.Lily. C.Emily. D.Paul.5.Thispassageismainly(主要地)aboutfourchildren’s________.A.goodfriends B.lovelytripsC.favoriteweather D.happyweekends五、补全对话（10分）21、根据对话内容，选择恰当的句子填入对话相应的空白处，使对话完整，合乎情景（有两个多余选项）。A:WhatcanIdoforyou,sir?B:___1___A:OK.Wenowhaveapples,grapesandbananasonsale.B:___2___A:Fiveyuanakilo.B:I’lltakesixapples.___3___A:Threekilos.___4___B:I’dliketobuysomegrapesformygrandparents.Howmucharethegrapes?A:Well,thegreenonesarethreeyuanakiloandtheredonesarefouryuanakilo.B:Twokilosoftheredones,please.A:Allright.B:___5___A:Thankyou.A.Here’sthemoney.B.Howmuchdotheyweigh?C.Wouldyouliketoeatsomegrapes?D.Iwantsomedrinks.E.Whatotherthingswouldyoulike?F.Iwantsomefruit.G.Howmucharetheapples?六、阅读表达（10分）22、回答问题，请注意要完整回答，语义齐全。Duringancient（古代的）times,childrendidn’thavesmartphones,iPadsorcomputerstoplay.Sotheyfoundsomethinginterestingtodo.Let’stakealook.Playingstoneballs（踢石球）DuringtheQingDynasty（清朝）FlyingkitesKiteshavealonghistory.Theearliestkitesweremadeof（由……制成）wood（木头）.It’sgettingpopulartoflyakiteinspringnow.ThethreemostpopularkitesaretheBeijingkite,TianjinkiteandWeifangkite.Hide-and-seek（捉迷藏）Hide-and-seekcanbringchildrenquitealotoffun.Therearetwowaystoplay:covering（遮盖）achild’seyeswhileotherkidsrunaroundtotease（逗弄）him,orsomechildrenhideandonechildmusttrytofindthem.Settingofffirecrackers（爆竹）Firecrackershaveahistoryofmorethan2,000years.Manyyearsago,therewasabeast（怪兽）namedNian.Toscareoff（吓跑）thebeast,peopleburnt（点燃）thefirecrackers.Firecrackersarestillsetoff（燃放）duringSpringFestivalnowadays.1.Whatdidthechildrenplayduringancienttimes?_____________________________________________________2.Whydidchildrenlovetoplayastoneballinwinter?_____________________________________________________3.Whatweretheearliestkitesmadeof?_____________________________________________________4.HowdochildrenfeelaboutHide-and-seek?_____________________________________________________5.Whendopeoplesetofffirecrackersnowadays?_____________________________________________________七、书面表达（20分）

暑假就要来了，你计划好了吗？请用英文写出你的假期计划。词数在70左右，短文开头已给出，不计入总词数。要点：Thesummervacationiscoming.___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

参考答案一、单项选择（共10小题，满分20分）1、B【解析】【详解】句意：做完家庭作业后，托尼要么下棋，要么散步。考查连词。so所以；or或者；that那个；if如果。either...or...“要么……要么……，或者……或者……”，固定搭配。故选B。2、B【解析】【详解】句意：——对不起，这附近有图书馆吗？——不，没有。但是你可以在朝阳街找到一个。考查一般疑问句。根据“istherealibrarynearhere?”可知为therebe句型的一般疑问句，其肯定回答为“Yes,thereis.”，否定回答为“No,thereisn’t.”。由答语“ButyoucanfindoneonChaoyangStreet.”可知此处应是否定回答。故选B。3、B【解析】【详解】句意：现在雨很大。幸运地是，我带了一把雨伞。考查副词。Easily容易地；Luckily幸运地；Differently不同地。根据“Itisrainingheavilynow,Itookanumbrella(雨伞).”可知，空前说下雨了，空后说我带了伞，故空处应表达幸运地。故选B。4、C【解析】【详解】句意：如果“herself”这个词出现在字典第958页上，“hurry”在第1002页，“hole”可能在976页面上。考查英文常识。herself，hurry，hole查字典时按照字母顺序进行查找，三个单词的第二个字母e排在前面，o排在中间，u排在最后，因此hole在字典中的位置应该在958—1002之间。结合实际，只有C符合要求。故选C。5、D【解析】【详解】句意：——Suzy，盒子里是什么？——打开它！这是给你的一个惊喜。考查介词辨析。beside在旁边；outside在外面；behind在后面；inside在里面。根据“Openit”可知问的是盒子里面是什么，所以要打开盒子。故选D。6、A【解析】【详解】句意：我们的学校演出在星期日下午6点。考查介词辨析。at在（几点）；on在（用在具体的某一天前）；in在（用在月份或年份等之前）。填空一处为时间点，应用介词at；填空二处，Sunday为具体的某一天，应用介词on。故选A。7、B【解析】【分析】【详解】句意：你怎么读“2547”？考查大数的表达。1000以上的基数词的表示法：先从右至左数，每三位数加一个逗点，第一个逗点代表thousand（千），第二个逗点代表million（百万），第三个逗点代表billion（十亿），这些单词和具体数字连用都不加“s”，排除A和C；在一百以上的数中，在hundred之后要用“and”，其他单位词之间不加“and”，故选B。8、B【解析】【详解】句意：以下哪一个“-ed”的发音与其他三个不同？考查语音知识。looked/lʊkt/；followed/ˈfɒləʊd/；rushed/rʌʃt/；passed/pɑːst/。根据音标可知，B选项“-ed”的发音与其他三个不同。故选B。9、—CouldyoucometomypartythisSunday?—Sorry,I________.Ihavetolookaftermylittlesister.A.couldn’t B.can’t C.mustn’t D.needn’t10、D【解析】【详解】句意：在下雨天，我不得不乘公共汽车去上学。考查介词辨析。at在；in在……里面；of属于……的；by通过，表示方式。根据空处后bus可知，是乘公共汽车，bybus表示“乘公共汽车”。故选D。二、完形填空（10分）11、1.D2.B3.A4.B5.C6.B7.A8.A9.C10.D【解析】【导语】本文主要介绍了锻炼的重要性，保持健康的方法以及锻炼可能会对人们造成的伤害。【1题详解】句意：健康非常重要。comfortable舒服的；boring无聊的；worth有价值的；important重要的。根据“Wemusthaveahealthybodyfirsttolivehappily”可知，有一个健康的身体才能快乐地生活，说明健康很重要，故选D。【2题详解】句意：我们如何保持健康？study学习；health健康；use使用；practice练习。前文讲述了健康的重要性，所以接下来会介绍保持健康的方法，故选B。【3题详解】句意：通过这种方式，我们可以更接近自然，享受新鲜空气。In在……里；At在；To到；For为了。inthisway“用这种方式”，固定搭配，故选A。【4题详解】句意：美丽的大自然会让我们快乐。sad难过的；happy开心的；sick生病的；rich富有的。根据“Thebeautifulnaturewillkeepus”可知，大自然让我们开心，故选B。【5题详解】句意：我经常做体育锻炼来放松我的身心。reply回复；reach到达；relax放松；research调查。根据“Ioftendophysicalexerciseto…mymindandbody”可知，做运动让自己身心都放松下来，故选C。【6题详解】句意：即使在一天的辛苦工作之后，我也会感觉很好，不会轻易生病。nervously紧张地；easily容易地；luckily幸运地；quickly快速地。根据“Ioftendophysicalexercise”及“getill”可知，经常做锻炼，不那么容易生病，故选B。【7题详解】句意：我经常做运动，所以我不会发胖。puton增加；putup张贴；workon对……有作用；workout解决。根据“Ioftendosports,soIwon’t…weight”可知，经常做运动不会长胖，故选A。【8题详解】句意：但是任何事有两面性。sides一边；ways方法；degrees度；habits习惯根据“Buteverythinghastwo”可知，任何事都有两面性，故选A。【9题详解】句意：我们可能会因为不够小心而伤害别人或自己。all都（三者以上）；any任何；other其他的；another另一个。根据“Wemayhurt…people”可知，可能会伤害其他的人，故选C。【10题详解】句意：更重要的是，太多的训练对我们的健康有害。should应该；can’t不可能；shouldn’t不应该；can能够。根据“toomuchtraining…doharm(伤害)toourhealth”可知，太多的训练能对我们的健康有害，故选D。三、完成句子（共5小题，满分10分）12、Heoftenhasbeefnoodlesforlunch【解析】【详解】he作主语，句子开头单词首字母大写；often频率副词，修饰动词；has...forlunch“吃……当做午餐”；beefnoodles“牛肉面”，作has宾语。故填Heoftenhasbeefnoodlesforlunch“他午餐经常吃牛肉面”。13、①.come②.up③.with④.solve【解析】【详解】comeupwith“想出”，为固定短语，情态动词can后加动词原形；solve“解决”，动词，空前有不定式符号，动词用原形。故填come；up；with；solve。14、tolearn【解析】【详解】句意：对我来说学好英语是容易的。本题中it作形式主语，动词不定式才是真正主语，所以此处使用learn的不定式形式tolearn，结构为“It’s+adj.+forsb.+todosth.”。故填tolearn。15、(d)irty【解析】【详解】句意：请打扫你的房间，因为太脏了。根据“Pleasecleanyourroom”及首字母提示可知，房间应是太脏了所以需要打扫，形容词dirty“肮脏的”符合句意。故填(d)irty。16、①.any②.more##longer③.full/filled④.of/with⑤.fat【解析】【详解】“别再……”not...anymore/longer；“都是”此处表示“充满”的意思，用fullof或filledwith；“脂肪”fat，不可数名词。故填any；more/longer；full/filled；of/with；fat。四、阅读理解（40分）17、1.B2.A3.B4.A5.A【解析】【导语】本文介绍了Leo的四个朋友周末的活动。【1题详解】细节理解题。根据第一行表格“Intheevening,Italkedtomyfriendonthephone.”可知，Mary周日晚上和朋友打电话，没有和朋友见面，故本题表述错误。故答案为B。【2题详解】细节理解题。根据第二行表格“OnSaturdayevening,wewenttoNancy’sbirthdayparty.”可知，周六晚上是Nancy的生日聚会，故本题表述正确。故答案为A。【3题详解】细节理解题。根据第三行表格“Ihadaboringweekend.Istayedathomeanddidsomehousework.”可知，Lily周末待在家做家务，没有去超市，故本题表述错误。故答案为B。【4题详解】细节理解题。通读全文可知，Mary，Lily和Tim周末都待在家（stayedathome），故本题表述正确。故答案为A。【5题详解】细节理解题。根据第二行表格“Ihadagreattime.”，结合Lucy描述和朋友一起玩的经历可知，Lucy周末和朋友过得很愉快，故本题表述正确。故答案为A。18、1.D2.B3.B4.C【解析】【导语】本文为一篇记叙文。文章主要讲述了一位农夫觉得自己的妻子很懒，但后来交换工作后发现自己错了的故事。【1题详解】细节理解题。根据“Sheaskedhimiftheycouldswap(交换)rolesforaday.”可知，她问他是否可以互换角色一天。故选D。【2题详解】细节理解题。根据“Hegotkicked(被踢)bythecow,hithisheadonthepigs’door,andforgottowashtheclothesandtakecareofthehen.”可知，他被母牛踢了一脚，头撞在猪的门上，还忘了洗衣服和照顾母鸡。由此可知，他不止一次受了重伤。故选B。【3题详解】词句猜测题。根据“Thefarmerfeltashamed.Heunderstoodthathewaswrongabouthiswife.Heshouldsaythankyouforherhardwork.Helearnedtorespect(尊重)herandneversaidmeanwordstoheragain.”可知，农夫感到很惭愧。他明白自己对妻子的看法错了。他应该对她的辛勤工作表示感谢。他学会了尊重她，不再对她说刻薄的话。所以“ashamed”的意思是“羞愧的”，故选B。【4题详解】主旨大意题。根据“Heshouldsaythankyouforherhardwork.Helearnedtorespect(尊重)herandneversaidmeanwordstoheragain.”可知，他应该对她的辛勤工作表示感谢。他学会了尊重她，不再对她说刻薄的话。由此可知，在我们的生活中，我们需要尊重他人的工作。故选C。19、1.A2.B3.D4.D【解析】【导语】本文介绍了作者在学校的课程和活动。【1题详解】细节理解题。根据“IfitisMonday,weusuallyhaveaflag-raising.Wesingthenationalanthem（国歌）andourschoolsong.”可知周一学生会升国旗，故选A。【2题详解】细节理解题。根据“Secondclass【3题详解】细节理解题。根据“Ithinkthemostdifficultclassisvisualarts（视觉艺术）”可知作者认为最困难的课程是视觉艺术，故选D。【4题详解】细节理解题。根据“Lunchbreak20、1.A2.C3.B4.D5.C【解析】【导语】本文中四个孩子谈论了自己最喜欢的天气。【1题详解】细节理解题。根据“Ienjoysunnyweather.Whenit’ssunny,Ifeelexcited.Icanrideabikeorgoforawalkwithmyfriends.”可知莉莉认为在晴朗的日子里去骑车是很好的。故选A。【2题详解】细节理解题。根据“DifferentfromLily,Ilikerainyweather.Itmakesmefeelrelaxedandforgetaboutsadthingsinmyeverydaylife.”可知安德烈在下雨天感到放松。故选C。【3题详解】推理判断题。根据“ButIlikesnow.Eachwinterinsnowyweather,Icanmakeasnowmanorgoskiing.Lastwinter,myfamilytookatriptoHarbin.Itwasveryexciting.”可知艾米丽喜欢雪，由此推出去哈尔滨的时候可能下雪了，所以艾米丽很兴奋。故选B。【4题详解】细节理解题。根据“Ienjoysummer.It’sjustrightforswimminginthepoolorhavingapicnicinthepark.”可知保罗喜欢在夏季去野餐。故选D。【5题详解】主旨大意题。本文中四个孩子谈论了自己最喜欢的天气。故选C。五、补全对话（10分）21、1.F2.G3.B4.E5.A【解析】【导语】本文是A和B之间的对话，B购买了一些水果。【1题详解】根据“Wenowhaveapples,grapesandbananasonsale”可知，下文介绍的是正在售卖的水果，据此推断顾客想买水果。选项F“我想要一些水果”符合情景，故选F。【2题详解】根据“Fiveyuan