2024秋高中英语Unit4Globalwarming同步练习含解析新人教版选修6

PAGE16-Unit4Globalwarming【导语】你知道全球变暖会给人类的生活和环境带来哪些改变吗？ShortandLongTermEffectsofGlobalWarming·ClimatechangeGlobalwarmingiscausingthetemperatureoftheearthtoriseslowly，causingmassiveglobalchangestoournaturalenvironment.·RisingsealevelGlobalwarmingisrapidlymeltingglaciersaroundtheglobe，causingarisingsealevelandpossiblycoastalfloodingandotherweatherproblemsinthefuture.·EcosystemchangesGlobalwarmingischangingcertainecosystemsthroughoutduetotemperaturefluctuations(波动)．Animalsandplantsarebeingforcedtoadapttothis，and，asaresult，aredyingoff.·Breakdownoftheozone(臭氧)layerGlobalwarmingiscreatingholesintheozonelayer，primarilyfromhumanuseofproductsthatemit(发出)poisonouschemicals.TheozonelayerabsorbsUVradiationfromthesun.Theholesarecausingamountsofpoisonouschemicalspresentinourbreathingairtoincreaseatarapidrate.【词海拾贝】1．dueto因为，由于2．adaptto适应3．dieoff相继死去4．atarapidrate以极快的速度【问题思索】True(T)orFalse(F)：1．Fiveeffectsofglobalwarmingarementionedinthearticle.()2．Manyanimalsandplantswillbeextinctasaresultofglobalwarming.()答案：1.F2.TⅠ.重点单词分类记★拼法高频单词1．________vi.同意；捐赠；订阅vt.签署(文件)；捐助2．________n．量；数量3．________vi.看一下；扫视n．一瞥4．________adj.平均的5．________n．环境；状况6．________n．种类；范围答案：1.subscribe2.quantity3.glance4.average5．circumstance6.range★联想拓展单词1．________vt.消费；消耗；耗尽；吃完→________n．消费者；顾客→________n．消费；消耗2．________adj.胡乱的；随意的→________adv.随意地，随意地3．________vt.反对；抗拒；与(某人)较量→________adj.反对的；对立的4．________adj.温顺的；温顺的；淡的→________adv.温顺地，和善地→________n．温顺；暖和5．________n．结果；后果；影响→________adj.随之发生的；作为结果的→________adv.因此，所以；结果6．________vt.陈述；说明→________n．声明；陈述7．________adj.平稳的；持续的；稳固的→________adv.平稳地；持续地8．________vi.趋向；易于；照看vt.照看；护理→__________n．倾向；趋势9．________n．生存；存在→________vi.存在，生存→________adj.目前的；现存的10．________n．承诺；交托；信奉→________vt.承诺；犯罪，做错事11．________n．污染；弄脏→________vt.污染→________adj.受污染的12．________n．增长；生长→________v．种植；生长；渐渐变得……13．________adj.电的；与电有关的→________adj.电的；电动的→________n．电；电流14．________n．教化工作者；教化家→________v．教化；培育→________n．教化；培育15．________n．贡献→________v．贡献出；投稿；捐献16．________n．显示，演出→________v．提出；呈现17．__________n．分歧；不一样→__________vi.不同意；不一样→________v．同意，赞成答案：1.consumeconsumerconsumption2．randomrandomly3.opposeopposed4．dness5.consequenceconsequentconsequently6.statestatement7.steadysteadily8.tendtendency9.existenceexistexisting10．mit11.pollutionpollutepolluted12．growthgrow13.electricalelectricelectricity14．cation15.contributioncontribute16.presentationpresent17.disagreementdisagreeagree★识记阅读单词1．graphn． _______________2．datan. _______________3．trendn. _______________4．catastrophen. _______________5．phenomenon(复数­ena)n.________________6．widespreadadj. _______________7．casualadj. _______________8．refreshvt. _______________答案：1.图表；坐标图；曲线图2.资料；数据3.趋势；倾向；走向4.大灾难；浩劫5.现象6.分布广的；普遍的7.随意的；漫不经心的；偶然的8.使复原；使振作Ⅱ.重点短语快速记1．________________发生；造成2．________________同意；预订；订阅3．________________大量的4．________________上升；增长；升起5．________________导致6．________________反对……7．________________即使8．________________接着9．________________大体上；基本上10．________________代表……一方；作为……的代言人11．________________忍受；容忍12．________________只要13．________________等等答案：1eabout2.subscribeto3.quantitiesof4．goup5.resultin6.beopposedto7.evenif8.keepon9．onthewhole10.onbehalfof11.putupwith12．solongas13.andsoonⅢ.经典句式应用记1．Thatprobablydoesnotseemmuchtoyouorme，butitisarapidincrease_______________(当与……相比的时候)othernaturalchanges.(状语从句的省略)2．______________________(毫无疑问)theearthisbecomingwarmerandthat________________(是人类活动)hascausedthisglobalwarmingratherthanarandombutnaturalphenomenon.(Thereisnodoubtthat...毫无疑问……；it's...that...强调句型)3．ItisOKtoleaveanelectricalapplianceon_____________(只要你在运用它)—ifnot，turnitoff！(solongas引导条件状语从句)答案：1.whencomparedto2.Thereisnodoubtthatitishumanactivitythat3.solongasyouareusingitⅠ.Fast­readingSkimmingforthemaininformation.1．Matchthegeneralideaofeachparagraph.Part1(Para.1)A．Twodifferentattitudes amongscientiststowards globalwarming.Part2(Paras.2to5) B．It'suptoreaderstodecide whetherpeopleshoulddo somethingaboutglobal warming.Part3(Para.6) C．Theintroductionofthe issueofglobalwarming.Part4(Para.7) D．Howhasglobalwarming comeabout?答案：Part1—CPart2—DPart3—APart4—B2．What'sthemaintopicofthearticle?A．Thetemperaturedifferencefrom1860to2000.B．Thecarbondioxidecontentintheatmosphere.C．Thewarmingoftheearth.D．Thereasonsforglobalwarming.答案：CⅡ.Careful­readingReadthetextcarefullyandthenchoosethebestansweraccordingtothetext.1．Whichofthefollowingstatementsiscorrectaccordingtothepassage?A．Thetemperaturerose5degreesFahrenheitfrom1860to2000.B．Thecarbondioxidecontentintheairincreasedby70partspermillionfrom1957to1997.C．AllthescientistsacceptthedatamadebyCharlesKeeling.D．JaniceFostersaysthatmorecarbondioxidewillmake.2．Whatmaybethebadeffectsofglobalwarmingaccordingtothepassage?A．Theremaybeariseofseveralmetresinthesealevel.B．Theremaybeseverestorms，floods，droughts，faminesorthespreadofdiseases.C．Theremaybethedisappearanceofspecies.D．Alloftheabove.3．WhichofthestatementsisTRUE?A．Naturalgasisagreenhousegas.B．Carbondioxideisabyproductofburningfossilfuels.C．Wearesureoftheeffectsofglobalwarmingnow.D．DrJaniceFosterbelievesthatglobalwarmingwilldogoodratherthanharmtotheearth.4．Thisarticleisfrom________．A．anenvironmentalmagazine B．adiaryC．anovel D．astory5．Accordingtothepassage，theglobalwarmingismainlydueto________．A．burningfossilfuelB．humanactivityC．havingtoomuchcarbondioxideintheskyD．somecatastrophes答案：1.C2.D3.B4.A5.BⅢ.Study­readingAnalyzethefollowingdifficultsentencesinthetext.1．Itmeansthatmoreheatenergytendstobetrappedintheatmospherecausingtheglobaltemperaturetogoup.[句式分析]本句是一个复合句。that引导一个________；causingtheglobaltemperaturetogoup为现在分词短语作_______。[尝试翻译]______________________________________________________________________________________________2．Ontheonehand，DrFosterthinksthatanytrendinwhichthetemperatureincreasesby5degreeswouldleadtoacatastrophe.[句式分析]①本句是一个主从复合句。②主句是DrFosterthinks，that引导________从句。③宾语从句中包含一个由inwhich引导的定语从句，修饰________。[尝试翻译]______________________________________________________________________________________________3．Ontheotherhand，therearethose，likeGeorgeHambley，whoareopposedtothisviewandbelievethatweshouldnotworryabouthighlevelsofcarbondioxideintheair.[句式分析]①本句是一个主从复合句。②主句是therearethose；who引导定语从句，修饰________且在从句中作主语；likeGeorgeHambley在句中作插入语。③在定语从句中，and连接两个并列的谓语areopposedto和believe，believe后跟that引导的________从句。[尝试翻译]______________________________________________________________________________________________答案：1.宾语从句结果状语这意味着更多的热量易于被困在大气层中，从而引起全球气温上升。2．宾语trend一方面，福斯特博士认为任何气温上升5度的趋势都可能导致一场大灾难。3．those宾语另一方面，还有一些人，像科学家乔治·汉布利，反对这种观点，他们认为我们不必担忧空气中高含量的二氧化碳。Ⅳ.Intensive­readingReadandfinishthepassagecarefully.ThetemperatureoftheearthroseaboutonedegreeFahrenheitduringthe20thcenturyandit'sarapidincreasewhen1.________(compare)toothernaturalchanges.Itishumanactivity2.________hascausedthisglobalwarming.Allscientiststaketheviewthattheburningoffossil3.________(fuel)causestheincreaseintheearth'stemperature.Themostimportantoneofthe“greenhouse”gasesiscarbondioxide，4.________cantrapheatfromthesunandwarmtheearth.Scientists'attitudestowardstheriseofcarbondioxideare5.________(complete)different.DrFosterthinksthatanytrendinwhichthetemperatureincreasesby5degreeswouldleadto6.________disaster.Atthesametime，othersthinktherewillbeariseinthesealevel，severestorms，floods，droughts，famines，thespreadofdiseasesorthe7.________(disappear)ofspecies.However，GeorgeHambley8.________(oppose)tothisview.Hebelievesthatweshouldn'tworryaboutit.Morecarbondioxidewillmakeplantsgrowquicker;cropswillproduce9.________(many);itwillencouragedifferentkindsofanimals.Allofthesewillmakelifeforhumanbeingsbetter.Greenhousegasescontinuetobuildupintheatmosphereandtheclimateisgoingtokeepon10.________(warm)fordecadesorcenturies.Nooneknowstheinfluenceofglobalwarming.答案：1pared2.that3.fuels4.which5pletely6．a7.disappearance8.isopposed9.more10.warming如何写英文海报海报是向大众发布某种消息的布告。海报的形式多为聘请广告、活动宣扬和人物介绍。英文海报的内容常为球讯、影讯、商业报道、展览会、报告会、专题讲座等。一、基本结构海报一般由标题、正文和落款三部分组成。1．标题。在第一行的正中间写上“POSTER”字样，接着在其次行即“POSTER”下面写上活动的详细名称或活动的内容。如：Anexcitingfootballmatch。2．正文。在第三行空4个字母格写正文，为一段。海报的正文要求写清晰以下内容：第一，活动的目的和意义。其次，活动的主要项目、时间、地点等。第三，参与的详细方法及一些必要的留意事项等。3．落款。要求写上主办单位的名称及海报的发文日期。二、留意事项1．时态：用一般将来时和一般现在时。2．语言：海报文字要求简洁明白，篇幅要短小精悍，文中可以用些鼓动性的词语，但不行夸大其词。3．要求：海报肯定要详细真实地写明活动的时间、地点、主要内容、参与规定及主办单位。【常用句式】①We'llhaveashow/footballmatchonJuly16th.②Thereisapieceofnewsthatwe'llholda．..＋地点＋时间．③Wehopetoraisemoneytohelpthepoorchildren...④Itwillbeheld...andthematchwillbewonderful.⑤Youcanbuyticketsin...andthepriceis2yuanforeach.⑥Bythen，somenewclothesareeven50%off.Ifyouspendmorethan100yuanatonetime，youcangetapresent.⑦Allarewarmlywelcome.⑧Everyoneiswelcome.⑨Catchthechance，oryouwillregret.⑩Signupandhaveagoodtime.请你用英语设计一张海报，内容80词左右，向同学们介绍一下夏令营的状况，并邀请同学们参与。要点如下：1．目的：使同学们学好英语，建立良好的人际关系；2．活动内容(学习英文歌曲、舞蹈、嬉戏等)；3．活动费用低。[审题谋篇]第一步明确要求这是一篇应用文——海报，写作要符合海报的特点。首先要标明海报的主题，即有一个洪亮而简洁的标题Englishsummercamp。文章的内容为对夏令营的介绍，即帮助学习英语、建立良好的人际关系；夏令营的优势——定期举办，费用低等；最终为海报的目的——邀请大家加入等内容不行或缺。最终，要留意落款——海报的组织方刚好间。其次步确定段落标题：Englishsummercamp主体：英语夏令营的内容、优势及目的。落款：学生会及海报日期。第三步提炼要点1．暑假thesummervacation2．英语夏令营Englishsummercamp3．致力于bedevotedto4．也aswellas5．人际关系interpersonalrelationship6．大量的avarietyof7．轻松的氛围inarelaxedatmosphere8．和某人相处很好getalongwellwithsb9．另外inaddition10．会费membershipfee第四步扩点成句1．夏令营的目的是提高会员的英语和成员间的人际关系。(一般表达)Theaimsofthesummercamparetoimproveitsmembers'Englishandinterpersonalrelationship.(句式升级1)Notonlythesummercampcangetitsmembers'Englishimproved，itcanalsomaketheinterpersonalrelationshipbetweenmembersbetter.(句式升级2)Thesummercampisdevotedtotheimprovementofitsmembers'Englishaswellastheestablishmentofgoodinterpersonalrelationship.2．每个暑假，该夏令营将举办英语歌曲学习、舞蹈培训和嬉戏等活动。(一般表达)EverysummerthecampwillteachmemberstolearnEnglishsongs，traindancesandplaygames.(句式升级1)Everysummer，aseriesofactivitieswillbeheldbythecamp，forexample，teachingEnglishsongs，trainingdancesandplayinggames.(句式升级2)Everysummer，thereareawidevarietyofactivities，suchasEnglishsongslearning，dancetrainingandgames.【范文点评】范文点评Englishsummercamp①Wouldyouliketospendthesummervacationyou’reyourfriends?AreyoueagertopracticeyourEnglishandgetyourspokenEnglishimprovedwhileenjoyingyourself?Comeon！②JoinusintheEnglishSummerCamp！TheSummerCampisdevotedto③theimprovementofitsmembers'Englishaswellastheestablishmentofgoodinterpersonalrelationships.Everysummer,thereareawidevarietyof④activities,suchasEnglishsongslearning,dancetrainingandgames.Inaddition⑤，themembershipfeeislow.Don'thesitateanylonger—joinusandenjoyyoursummervacation！⑥SchoolStudentUnionJune7，2024⑦范文文章格式正确，行文规范；文章有血有肉，长短句结合得好，运用了省略句、祈使句、倒装句等；文中用词精确，语言地道，有许多关于词汇的用法值得我们积累。①海报标题恰如其分，宣扬夏令营；②正文开头敏捷运用问句，使海报内容显得不呆板，同时又能起到渲染的作用；③bedevotedto高级词汇，增加作文亮点；④awidevarietyof“各种各样的”，表明作者的语言功底；⑤inaddition“另外，此外”，上下文连接好；⑥祈使句，丰富文章句式，发出邀请，希望大家参与活动；⑦结尾符合海报格式请依据下列内容写一张海报。全球变暖问题越来越引起人们的关注，它所产生的严峻后果也渐渐为人所知。为此，你校学生会特意邀请了环保专家来校举办讲座，特地就全球变暖问题产生的缘由、后果，以及中学生如何应对全球变暖等问题进行论述，并在演讲结束后回答同学们的提问。时间：星期五8：00am—11：00am地点：大厅留意：1.词数80左右；2．可以适当增加细微环节，以使行文连贯。________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________答案：AlectureonglobalwarmingOrganizedbytheStudents'Unionofourschool,alectureonglobalwarmingwillbegiveninthehallonFriday，from8：00amto11：00am.Anexpertworkingfortheenvironmentwillgivealectureonthecausesandtheharmfuleffectsofglobalwarming.Besides，hewillstatewhatwecandowiththeproblem.Attheendofthespeech，wecanaskhimsomequestionsaboutglobalwarming.Allarewelcome!Students'UnionThursdayA级基础过关Ⅰ.单句语法填空在句中空白处填上适当的内容(1个单词)或括号内单词的正确形式。1．The________(present)ofprizesbeganafterthespeeches.2．More________(important),wecansharetheinformationwithallofyou.3．Youmayusetheroomasyoulike________longasyoucleanitupafterwards.4．Wehaven'tdecidedwhether________(go)campingnextweek.5．John'ssuccesshasnothingtodowithgoodluck.Itisyearsofhardwork________hasmadehimwhatheistoday.答案：1.presentation2.importantly3.so/as4.togo5.thatⅡ.选词填空andsoon；ifso；underthecircumstances；aslongas；onbehalfof1．Sinceheissoimportantafigure,nobodycanbe_______him.2．Thisshopsellsclothes,shoes,hats，___________________.3．HaveyouevervisitedThailand，and__________，when?4．_______________，you'dbetternottellhimthebadnews.5．Shewillgotohisbirthdayparty________sheisinvited.答案：1.onbehalfof2.andsoon3.ifso4.Underthecircumstances5.aslongasⅢ.依据汉语完成句子1．Theyoungmanwillcometotheparty______________．那个年轻人将代表他家人来聚会。2．Idon'tknowhowpeoplearoundtheairport_________madebyplanes.我不知道机场四周的人们是如何忍受飞机发出的噪音的。3．_______________youtellmethetruth，I'lltrytohelpyou.只要你说实话，我会尽力帮助你。4．Ifyoudosoitwill________________________．假如你那样做，影响就大了。5．Theygottogethertodiscuss______________________．他们聚在一起探讨如何实施安排。答案：1.onbehalfofhisfamily2.putupwiththenoise3．Aslongas4.makeagreatdifference5.howtocarryouttheplanB级实力提升Ⅰ.阅读理解阅读下面短文，从每题所给的四个选项(A、B、C和D)中，选出最佳选项。InternationalpopstarandUNICEFGoodwillAmbassadorKatyPerryhasreleasedaspecialreportonman­madeclimatechange—andit'slikelytobemuchhotterthanyouexpect.Inavideothatimitatesthetelevisionnews，the“HotandCold”singersaidtheeffectsofextremeweatherpatternsarehavingonmillionsofchildrenaroundtheworld.“AsaCaliforniaGirl，I'mnottheonlyoneexperiencingdrought，”thesuperstarsays.Thesongstress(女歌手)takesviewersona60­secondglobaltour，beginninginthePhilippines，wheretropicalcyclonepatterns(热带气旋气候)havedamagedtheregionseverely.FromthereshegoestoBangladesh，wherefloodinghasleftmillionsofchildrenandfamilieswithouthomes.InEastAfrica，mosquito­bornemalaria(通过蚊子进行传播的疟疾)continuestospreadwhileanamazing800childrendiebythediseaseeveryday，shenotes.“Andtheforecastis：conditionswillworsen，”Perryworriedlyconcludes.“Let'sencourageourworldleaderstotakethisissueseriously，”shesaidinareleasefollowingthevideo.“Shareyourstoryonhowyouarehelpingreduceclimatechange.Togetherwecanhelpchangetheforecastformillionsofchildren.”Thereport'ssurprisingfindingsareamongUNICEF'slatestreportonclimatechange，releasedinNovember.Thevideo'sreleaseonSundaycomesasworldleadersconveneinParisatCOP21，the21stsessionoftheConferenceoftheParties.There，morethan190nationshavegatheredtodiscussapotentialnewglobalagreementonclimatechange.The“DarkHorse”singerwasappointedambassadortoUNICEFin2013.Thatsameyear，shetravelledtoMadagascarwhereshespenttimeteachingandplayingwithchildrenattendingUNICEFprogrammesattheIlaikoChildProtectionCentre.【语篇解读】近日，国际流行歌星、联合国儿童基金会(UNICEF)亲善大使凯蒂·佩里发布了一段关于人为气候改变的特别播报视频，呼吁大家关注气候改变——全球气候可比你想象的要热多了。1．KatyPerryisnot________．A．aninternationalpopstarandUNICEFGoodwillAmbassadorB．thesingerof“HotandCold”and“DarkHorse”C．aCaliforniaGirlD．aweatherforecaster解析：细微环节理解题。依据其次段开头“Inavideothatimitatesthetelevisionnews”在一段仿照电视新闻播报的视频中可知她不是一名天气预报员。答案：D2．WhichoneofthefollowingplacesisNOTwherethesongstresstakesviewersona60­secondglobaltour?A．ThePhilippines. B．Bangladesh.C．EastAfrica. D．Madagascar.解析：细微环节理解题。依据第三段可知A、B、C三项是视频中去过的地方，D项出现在最终一段明显不是。答案：D3．Wherecanwefindthereport'ssurprisingfindings?A．Avideothatimitatesthetelevisionnews.B．UNICEF'slatestreportonclimatechangereleasedinNovember.C．The21stsessionoftheConferenceoftheParties.D．TheIlaikoChildProtectionCentre.解析：细微环节理解题．依据第五段“Thereport'ssurprisingfindingsareamongUNICEF'slatestreportonclimatechange，releasedinNovember.”可知播报中提及的让人震惊的数据源自UNICEF在11月发布的一篇关于气候改变的最新报告。答案：B4．Whichoneisthebesttitleforthepassage?A．KatyPerryCallsforActiononClimateChangeinUNICEFVideoB．ASpecialReportonMan­madeClimateChangeC．A60­secondGlobalTourD．TheCOP21onClimateChange解析：主旨大意题。本文主要介绍了国际流行歌星、联合国儿童基金会(UNICEF)亲善大使凯蒂·佩里发布了一段关于人为气候改变的特别播报视频，呼吁大家关注气候改变。答案：AⅡ.七选五依据短文内容，从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。(2024·全国卷Ⅰ)IfanyonehadtoldmethreeyearsagothatIwouldbespendingmostofmyweekendscamping，Iwouldhavelaughedheartily.Campers，inmyeyes，werepeoplewhoenjoyedinsectbites，ill­cookedmeals，anduncomfortablesleepingbags.Theyhadnothingincommonwithme.__1__Thefriendswhointroducedmetocampingthoughtthatitmeanttobeapioneer.__2__Wesleptinatent，cookedoveranopenfire，andwalkedalongdistancetotaketheshowerandusethebathroom.ThisbriefvisitwithMotherNaturecostmetwodaysofffromwork，recoveringfromabadcaseofsunburnandthedoctor'sbillformyson'sfoodpoisoning.Iwas，nevertheless，talkedintogoingonanotherfun­filledholidayinthewilderness.__3__Instead，wehadapop­upcamperwithcomfortablebedsandanairconditioner.Mynature­lovingfriendshadrememberedtobringallthenecessitiesoflife.__4__Wehavedonealotofitsince.Recently，weboughtatwenty­eight­foottraveltrailercompletewithabathroomandabuilt­inTVset.Thereisaseparatebedroom，amodernkitchenwitharefrigerator.Thetrailerevenhasamatchingcarpetandcurtains.__5__Itmustbetruethatsoonerorlater，everyonefindshisorherwaybacktonature.Irecommendthatyoufindyourwayinstyle.A．Thistimetherewasnotent.B．Thingsaregoingtobeimproved.C．Thetriptheytookmeonwasaroughone.D．Iwastolearnalotaboutcampingsincethen，however.E．ImustsaythatIhavecertainlycometoenjoycamping.F．Afterthetrip，myfamilybecamequiteinterestedincamping.G．Therewasnoshadeasthetreeswerenomorethan3feettall.【语篇解读】作者最初不宠爱野营，经过几次有打算的野营后，渐渐宠爱上它了。1．解析：前面提到野营的缺点，这些是作者三年前的相识。此处表示转折，然而，自从那时以来我对野营有了更多的相识。then指代前面提到的threeyearsago。答案：D2．解析：空后面提到这次野营住在帐篷里，在户外做饭，走很远的路去洗澡，回家后两天没有上班，一是因为被晒伤，二是儿子食物中毒。这都说明这次野营对作者来说是很难的一次。故选C。答案：C3．解析：依据空后面的“wehadapop­upcamperwithcomfortablebeds”说明这次没有帐篷。故选A。答案：A4．解析：此处承接上文，表示自从那一次野营后，我一家人就对野营感爱好了。引出空后面一句“wehavedonealotofitsince.”(自从那时以来我们去野营多次了)。答案：F5．解析：最终一段是总结，前面提到作者对野营从不宠爱到宠爱的一个过程，所以此处作者得出结论：我必需承认我起先宠爱野营了。答案：EⅢ.完形填空阅读下面短文，从短文后各题所给的四个选项(A、B、C和D)中，选出可以填入空白处的最佳选项。Whennatureisleftalone，abalanceisreachedamongtheanimalsandplantslivinginonearea.Butwhenmanstartshisworkinnature，thebalanceislikelytobe__1__．Hegrowsacropandtakesitawaytoeat；thenthereareno__2__leavestofallontheground，decaying(腐烂)andaddinghumus(腐殖质)tothesoil.__3__afarmeractswithknowledgeandskill，heisthereforemostlikelytomakethelandpoorer.To__4__theusefulmatterinthecropsthathe__5__，heusessomekindoffertilizer.Chemicalfertilizersare__6__，butdecayingremainsofplantsshouldalsobeputontheland.Insomeplaces，it'sa__7__toburnwastemateriallyingabout，butsuchburningdestroysthe__8__matterinthedeadplants.Althoughthe__9__thatareleftare__10__whenputontheland，abetter__11__istoburythewastesothatitdecaysandincreasesthehumusinthesoil.Inthepast，whentheworld__12__wasmuchlowerthanitisnow，amanhadlittledifficultyinordinarytimesin__13__thefoodthatwasneeded.Whenafieldhadbeenusedforsomeyearsandhadbecome__14__，thefarmercouldmovetoanother__15__．Thetiredlandthenslowly__16__．Graduallygrassesandotherplantswouldappearonitandits__17__powerwouldslowlyreturnto__18__throughtheirdecay.Butnature，leftalone，wouldtakealongtimetobringbackthelandtoits__19__state；thelengthoftimerequiredwoulddependonlocalconditions，butitmightwellbetenyears.The__20__forcropsinmoderndaysisheavy，andtenyearsistoolongforafarmertoleavehislandlyingidle(闲置的)．Ifthefarmerwantshislandtoberestoredmorequicklythannaturealonewilldoitforhi