【文档说明】2 UNIT 4 Section Ⅱ Listening and Speaking & Reading and Thinking—Language Points-(新教材)高中英语人教版必修2 .doc,共(12)页,684.500 KB,由小喜鸽上传
转载请保留链接:https://www.ichengzhen.cn/view-119108.html
以下为本文档部分文字说明:
SectionⅡListeningandSpeaking&ReadingandThinking—LanguagePointspuzzlen.谜;智力游戏;疑问vt.迷惑;使困惑(教材P40)GettingtoknowalittlebitaboutBritishhistory
willhelpyousolvethispuzzle.了解一点英国历史将有助于你解决这个难题。(1)beinapuzzle感到困惑beapuzzletosb.对某人来说是个谜(2)puzzleabout/over苦苦思考
(3)puzzledadj.困惑的,迷惑不解的puzzlingadj.令人迷惑不解的①Whatpuzzledmewashowtheaccidentcouldhavehappened.令我感到困惑的这个事故是怎么发生的。②I’minapuzzleastohowtogetalongwith
him.对如何和他相处使我感到困惑。[即学即练]——单句语法填空①Youmusthavebeentroubledbywhentosay“Iloveyou”becauseitisoneofthegreatestpuzzles(pu
zzle)inourlife.②Theirreasonfordoingitisstillapuzzletome.③Thesescientistshavebeenpuzzlingabout/overhowtosolvetheenvironmentalproblem.④Thepuzzled
lookonherfacesuggestedshewaspuzzlingoverthepuzzlingmathsproblem.(puzzle)join...to...把„„和„„连接或联结起来(教材P40)Inthe16thcentur
y,thenearbycountryofWaleswasjoinedtotheKingdomofEngland.16世纪,附近的威尔士并入英格兰王国。(1)jointhearmy/club参军/加入俱乐部joinin参加(比赛、活动
等)(2)connect...with...把„„和„„联系起来①Theisland,joinedtothemainlandbyabridge,iseasytogo.岛上有一座桥与大陆相连,去那里很方便。②Peopleallovertheworldusuallyconn
ectChinawithsilkandgoodfood.世界各地的人们通常把中国与丝绸和美食联系在一起。[链接写作]——完成句子①Itissaidthatmorethantwohundredstudentshavejoined_in_the_
discussion(参加讨论).②AsfarasIknow,itisfiveyearssincehejoined_the_army(参军).breakaway(fromsb./sth.)脱离;背叛;逃脱(教材P40)Finally,inthe20thcentur
y,thesouthernpartofIrelandbrokeawayfromtheUK,whichresultedinthefullnamewehavetoday:theUnitedKingdomofGreatBrit
ainandNorthernIreland.最后,在20世纪,爱尔兰南部脱离英国,这导致了我们今天有的英国的全名:大不列颠及北爱尔兰联合王国。breakdown损坏;发生故障;分解;累垮breakinto破门而入breakout(战争)爆发;(火灾)突然发生breakup
结束;破裂①However,thesouthernpartofIrelandwasunwillingandbrokeawaytoformitsowngovernment.然而,爱尔兰的南部不愿意组建联合王国,它分离
出去并建立了自己的政府。②Ittookgreatcouragetobreakawayfromhisfamilyatthattime.在那时与家庭决裂需要勇气。[即学即练]——用break的相关短语填空①Ifyougoonworkinglikethat,youwillbreak_dow
nsoonerorlater.②Afirebroke_outinthishotellastnightandthreepeoplewerekilled.③Withsomanyproblemsunsettled,af
ewcountrieswantedtobreak_away_from_theUnion.④Inmyopinion,marriagebasedonmoneyislikelytobreak_up.belongto属于(教材P40)Thefourco
untriesthatbelongtotheUnitedKingdomworktogetherinsomeareas.属于英国的四个国家在某些领域进行合作。(1)belongto表示“属于”,不能用于进行时态和被动语态(2)belongingsn.财
产,所有物①Nomatterwhathappens,TaiwanbelongstoChina.不论发生什么事情,台湾都属于中国。②ProfessorWilliamskeepstellinghisstud
entsthatthefuturebelongstothewell-educated.威廉姆教授一直告诫他的学生们未来属于受过良好教育的人。[即学即练]——单句语法填空①Asisknowntous,Chinaisacountrybel
onging(belong)tothethirdworld.②Myfriendwillhelpyoumoveyourbelongings(belong)toyournewhouse.[链接写作]——完成句子③(2017·全国卷Ⅱ)剪纸有1500多年的历史,属于中国的传统艺术。P
aper-cuttinghasahistoryofover1,500years,which_belongs_totraditionalartinChina.belongto中的to是介词,该短语既不能用于被动语态,也不能用
于进行时态;作后置定语时,形式为“...belongingto”。defencen.防御;保卫(经典佳句)Indefenceofourmotherland,alargenumberofpeoplelosttheirlives.为了
保卫我们的祖国,许多人失去了生命。(1)indefence(of...)为了保卫(„„)(2)defendvt.保护;保卫;为„„辩护defend...from/against...防御;保卫„„以免受„„①Allthepeoplewerefig
htingagainstthefloodindefenceoftheirownhomes.为了保卫自己的家园,所有的人都在与洪水作斗争。②HehasemployedoneoftheU.K.’stoplawyerstodefendhim.他请了英国一位顶尖律师为他辩护。[即学即练]——单
句语法填空①Somethinkthatstudentsshouldbetrainedto_defend(defend)themselvesagainstsomeattacks.②Themonumentisinmemoryofthesoldierswhodiedinde
fence(defend)oftheircountry.③Whenadogattackedme,Ipickedupasticktodefendmyself(I).surroundvt.围绕;包围(教材P40)AlmosteverywhereyougointheUK,youwillbesu
rroundedbyevidenceoffourdifferentgroupsofpeoplewhotookoveratdifferenttimesthroughouthistory.几乎无论你走到英国的任何地方,你都会发现历史上
有四种不同的人在不同的时期统治过英国。(1)surround...with...用„„包围„„besurroundedwith/by...被„„包围/环绕(2)surroundingadj.周围的;附近的(3)surroundingsn.环境;周边事物(复数)①Thepr
ofessorlikestosurroundhimselfwithhisstudents.那位教授喜欢和他的学生们在一起。②Thesmallvillageissurroundedwithgreenmount
ainsandclearrivers,attractingvisitorsfromeverycorner.青山绿水环抱着村寨,吸引着各方来客。[即学即练]——单句语法填空①Surrounded(surround)bytheforest,the
villagelooksverybeautiful.②Livinginbeautifulandcomfortablesurroundings(surround),wefeelveryhappy.③Theyallwentouttolookforthe
lostchildinthesurrounding(surround)villages.evidencen.证据;证明(经典佳句)Thereisnowconvincingevidencethatsmokingca
useslungcancer.现在有令人信服的证据证明吸烟导致肺癌。(1)Thereissomeevidencethat...有证据证明„„(2)evidentadj.明显的,明白的It’sevidentthat...很明显„„①Modernsciencehasgiv
enclearevidencethatsmokingcanleadtomanydiseases.现代科学对吸烟能导致多种疾病已经给出了明确的证据。②Itisevidentthatthemanishighlythoughtofinthecompany.很显然,这个人在公司里受到高度评价。[链接写
作]——完成句子有证据显示,进行户外活动对我们有好处。There’s_some_evidence_thatoutdooractivitiesaregoodforus.achievementn.成就;成绩;达到(教材
P40)Someoftheirgreatachievementsincludedbuildingtownsandroads.他们的一些伟大成就包括建设城镇和道路。(1)asenseofachievement成就感makeanachievement取得成就(2)achi
evevt.完成;达到vi.成功achieveone’sgoal达到目标①Evenasmallsuccesscangiveyouasenseofachievement.即便是小小的成功也能给你一种成就感。②H
islazinessmakesitimpossibleforhimtoachievehisgoal.他的懒惰使他不可能达到目标。[即学即练]——单句语法填空①ThewomanscientistwasawardedtheNobelPrizeforph
ysicsforthosegreatachievements(achieve)madebyher.②We’vehadagoodstart,butmoreworkneedstobedoneto_achieve(achieve)thefinalsuccess.
if条件状语从句的省略形式(教材P40)Sowhatisthedifferencebetweenthem,ifany?如果有的话,那么它们之间有什么区别呢?ifany如果有的话ifso如果这样的话ifnot如果不这样的话ifnecessary如果有必要的话i
fpossible如果有可能的话①Theremaybesomemistakesinmycomposition.Ifany,pleasehelpmepointthemout.我的作文可能有些错误。如果有的话,请帮我指出来。②Didyoucheatintheexam?Ifso,youwon’tget
awaywithit.你在考试中作弊了吗?如果这样的话,你将不会逃脱惩罚。[链接写作]——完成句子(2018·全国卷Ⅰ)我是李华,我想知道周末你是否有空。如果有空咱们面谈有关餐桌礼仪的问题。I’mLiHua.I’mwonderingifyouareavailable
attheweekend.If_so,_let’s_have_a_face_to_face_talk_abouttablemanners.aswellas既„„又„„,连接并列成分(教材P40)Theyusethesameflag,kn
ownastheUnionJack,aswellassharethesamecurrencyandmilitarydefence.他们使用同一面国旗,也就是英国国旗,也拥有同样的货币和国防。(1)knownastheUnionJack为过去
分词短语作后置定语,修饰名词flag;(2)aswellas既„„又„„,可连接两个平行结构。动词形式与aswellas之前的主语一致;(3)aswellas连接并列主语时谓语动词与前面的主语一致。①YangLiwei,knownasthefirstChinesea
stronauttogotospace,isregardedasanationalhero.杨利伟,作为中国第一个进入太空的宇航员,被认为是国家英雄。②MyfatheraswellashisworkmateshasbeentoBeijing.我父亲和他的同事曾去过北京。[即学即练]——
单句语法填空①Greatscientificachievementswillhaveapositiveeffectonourlifeaswellassociety.②(2019·天津卷)Amy,aswellasherbrothers,was_given
(give)awarmwelcomewhenreturningtothevillagelastweek.theway后省略that/inwhich的定语从句(教材P40)TheyintroducedthebeginningsoftheEnglishlan
guage,andchangedthewaypeoplebuilthouses.他们介绍了英语的起源,改变了人们建造房屋的方式。(1)句中定语从句peoplebuilthouses修饰先行词theway,其前省略了
关系词that/inwhich;(2)theway作先行词,如果在定语从句中作主语,引导词为that/which且不能省略;(3)theway作先行词,如果在定语从句中作宾语,引导词为that/which且可以省略。①Thestudentsdidn’tunders
tandtheway(that/inwhich)themathsteachersolvedtheproblem.学生们没有理解数学老师解答该题的方法。②I’dliketosettletheprobleminawaywhich/thatispeaceful.我想用和平的方法解决这个问题。[链
接写作]——一句多译我不喜欢她跟你讲话的方式。①Idon’tlikethe_way_she_speaks_toyou.②Idon’tlikethe_way_in_which_she_speaks_toyou.(inwhich引导的定
语从句)③Idon’tlikethe_way_that_she_speaks_toyou.(that引导的定语从句)Ⅰ品句填词1.Astheoldsayinggoes,“Together,individuals(个人)canmake
adifference.”2.TheUnitedKingdom(王国)ofGreatBritainandNorthernIrelandismadeupofEngland,Wales,ScotlandandNorthernIreland.3.Heworksasachief(主要的)edi
torinChinaDaily.4.Thecountryneedsadefence(防御)capabilityasinsuranceagainsttheunexpected.5.Mymotherworksinanearby(附近的)companyandsheusuallywalkshome.
6.Thelocation(位置)oftheArtsTheatrewasconsideredapoorareaoftown.7.Theywereunwillingtoacceptthefactthattheirsondiedinthebattle(战斗,战役).8.Asisknownt
ous,Qingdaoisabeautifulport(港口)citywithalonghistory.9.Asisknowntoall,Chinahasmadegreatachievements(成就)duringthepastdecades.10.Tim’spuzzled
(困惑的)expressionsuggestedthathedidn’tunderstandwhattheyhadsaid.Ⅱ完成句子/一句多译1.在过去的几年里,中国在环保方面取得了巨大成就。Inthelastfewyears,Chinahasmade_great_ac
hievements_in_environmental_protection.2.我们可以更多地了解伟人的生活以及其他国家的历史和文化。Wecanknowmoreaboutthelifeofgreatpeopleas_well_as_history_and_cul
tures_ofothercountries.3.著名科学家袁隆平于2019年9月29日被授予共和国勋章。YuanLongping,known_as_a_famous_scientist,_wasawardedNationalMedalsonSeptember29th,2019.4.保
持环境清洁无污染是使人们生活健康的关键一步。Keeping_the_environment_clean_and_free_of_pollutionisthekeysteptomakelifehealthy.5.温哥华是加拿大最温暖、
最美丽的城市。它被群山和太平洋环绕。(1)VancouverisCanada’swarmestandmostbeautifulcity.Itis_surrounded_by_mountains_and_the_Pacific_Ocean.(2)V
ancouverisCanada’swarmestandmostbeautifulcity,which_is_surrounded_by_mountains_and_the_Pacific_Ocean.(合并升级为定语从句)Ⅲ课文
语法填空StudyingBritishhistorycanhelpyouunderstand1.whattheUnitedKingdom,GreatBritain,Britain,Englandmean.Inth
e16thcentury,WaleswasjoinedtotheKingdomofEngland.Inthe18thcentury,Scotlandwasjoined2.to_create(create)theKingdomofGre
atBritain.Inthe19thcentury,theKingdomofIrelandwasaddedtocreatetheUnitedKingdomofGreatBritainandIreland.However,thesouthernparto
fIrelandbroke3.away_fromtheUK,whichresulted4.inthefullnamewehavetoday:theUnitedKingdomofGreatBritainandNorthernIre
land.Althoughthefourcountriesworktogetherinsomeareas,theystillhavesome5.differences(different).TheUnitedKingdomhasal
ongandinterestinghistorytoexplore,6.whichcanhelpyouunderstandmuchmoreaboutthecountryand7.its(it)traditions.Nomatterwhereyo
ugointheUK,youwill8.be_surrounded(surround)byevidencethatfourdifferentgroupsofpeoplewhotookoveratdiffer
enttimesthroughouthistory.Studyingthehistoryofthecountrywillmakeyourvisitmuchmore9.enjoyable(enjoy).TheUKisafasci
natingmixofhistoryandmodernculture,withbothnewandold10.traditions(tradition).Ⅰ单句语法填空1.Whenhewokeup,h
efoundhimselfsurrounded(surround)bysomedoctors.2.Ifyoucontinuetodoillegal(legal)things,youwillendupinprisonsoonerorlater.3.Iamquiteconfused(confu
se)byChinesetablemanners.I’dappreciateitifyoucouldgivemesometipsonhowtobehaveproperlyatadinnerparty.4.Aswellasstudying
(study)Englishatschool,AlicetaughtherselfJapaneseathome.5.Shesteppedbackappearingsurprisedandputupherhands,asifindefence(defend).6.Thereisevi
dence(evident)thatBeijingManusedfiretocookfood.7.Hepassedthecollegeentranceexamination,whichmadehisparentsveryproud.8.Thereis
somuchmoreto_learn(learn)abouttheinterestinghistoryandcultureoftheUnitedKingdom.9.Hewasveryupset(upset)becausehispenpaldidn’treplytohislett
ersintime.10.Haveyoueverbelonged(belong)toapoliticalparty?Ⅱ阅读理解AOttawaisthecapitalofCanada.ItisthesecondlargestcityinOntarioandthefourth
largestcityinthecountry.TheCentreBlockisthemainbuildingonParliamentHill(国会山).Itisalsothelocationofseveralceremonialspaces,suchastheH
allofHonorandtheMemorialChamber.ThepresentCentreBlockistheseconditerationofthebuilding,afterthefirstwasdestroyedbyfi
rein1916,anditisoneofthemostrecognizablebuildingsinCanada.DowntownOttawaisthecommercialandeconomiccentreofthecity.Mostof
thebuildingsareofficetowers.WhilemostofOttawa’shightechindustryisbasedelsewhere,ithasasignificantpresenceinthedowntownc
ore.Thedowntownalsocontainsanumberofapartments,hotels,andtheoldersinglefamilyhomesandtownhousesalongitsedges.TheNation
alGalleryofCanadaisoneofCanada’spremierartgalleries.TheGalleryhasalargeandvariedcollectionofpaintings,drawings,sculptureandphotographs.Althou
ghitsfocusisonCanadianart,italsoholdsworksbysomenotedAmericanandEuropeanartists.TheRideauCanalistheo
ldestcontinuouslyoperatedcanalsysteminNorthAmerica.Attheverybeginning,thepurposeoftheRideauCanalwasmilitary,asitwa
sintendedtoprovideasecuresupplyandcommunicationroutebetweenMontrealandtheBritishnavalbaseinKingston.Itremainsinusetodayprima
rilyforpleasureboating,withmostofitsoriginalstructuresundamaged.Thelocksonthesystemopenfornavigationinmid-May
andcloseinmid-October.【解题导语】文章描写了加拿大渥太华著名的几处地方,并分别对这几处地方进行了详细的说明。1.Theunderlinedword“iteration”inthe2ndparagraphprobablymeans
“________”.A.repairB.designC.copyD.landmarkC解析:词义猜测题。从第二段ThepresentCentreBlockistheseconditerationofthebu
ilding,afterthefirstwasdestroyedbyfirein1916可知,现如今的中央街区是重新翻修的,以前的那一座在1916年的大火中被毁坏了。所以iteration的意思相当于copy,复制品。故选C。2.InthecoreofDown
townOttawa,wecouldsee________.A.alargenumberoftalltowersB.headofficesofOttawa’shightechindustryC.anum
berofapartmentsandhotelsD.theoldersinglefamilyhomesandtownhousesB解析:细节理解题。根据文章第三段中的Mostofthebuildingsareoffic
etowers.WhilemostofOttawa’shightechindustryisbasedelsewhere,ithasasignificantpresenceinthedowntowncore.可知在渥太华的市中心都是办公大楼,而且主要是高科技行业的办公大
楼。3.CollectionsintheNationalGalleryofCanadaaremainly________.A.paintingsanddrawingsB.sculptureandphotographsC.worksbyCa
nadianartistsD.artworkbyAmericansandEuropeansC解析:细节理解题。根据倒数第二段中的TheGalleryhasalargeandvaried...Altho
ughitsfocusisonCanadianart,italsoholdsworksbysomenotedAmericanandEuropeanartists.可知,主要收藏的是各种各样的画以及雕像、照片。它主要是收藏加拿大人的艺术作品,同时也收藏一些著名的美国人和欧洲人的作品,故选C。
4.WhichofthefollowingisTRUEabouttheRideauCanal?A.ItistheoldestcanalsysteminNorthAmerica.B.Itwasoriginallyforthemilitarypurpose.C
.Theoriginalstructuresremainneverchanged.D.PeoplecanonlygoboatingfromMaytoOctober.B解析:推理判断题。根据最后一段中的Attheverybegin
ning,thepurposeoftheRideauCanalwasmilitary可知,最初的目的是军事目的。BYou’llbelikelytobecomeangryifyoudon’tgetagoodnight’s
sleep,anewpaperreports.Cuttingafewhoursofsleepoutofyourscheduleisn’tasgoodanideaasitmayappear.ResearchersattheIowaState
Universityreportthatmissingsleepwillmakeyouangrier,leavingyouill-equippedtodealwithuneasysituations.Thisisoneofthefirststud
iestoprovideevidencethatsleeplosscausesanger.Thelinkbetweenlack(短缺)ofsleepandnegativemoods(angerincluded)hasbeenprov
edinpastresearch,buttheproblemisthatweknowthatthetwocometogether,butnotthatwhetheronecausestheother.Inthecurrentstudy,Krizanandco-authorGarret
tHisler,anISUdoctoralstudent,dealwiththisquestion.Underthestudy,volunteersweredividedintotwogroups.Theco
ntrolgroupfollowedtheirnormalsleeproutine,whiletheexperimentalgroupcuttwotofourhoursofsleepeachnightfortwonights.Onave
rage,thecontrolgroupgotalmostsevenhoursofsleepanight,whiletheexperimentalgroupgotaboutfourandahalfhourseachnight.Inordertomeasureanger,the
yhadvolunteersvisitthelabbeforeandafterthesleepmanipulation(操纵).Allthewhile,theywereaskedtolistentosomeunpleas
antbrownandwhitenoise.Krizansaysthepurposewastocreateuncomfortableconditions.“Ingeneral,angerwasmuchhigherforthosewhosesleepwasrestricted(限制),
”Krizansaid.“Wemanipulatedhowunpleasantthenoisewasduringthetask.Asexpected,volunteersreportedmoreangerwhenthenoisewasmoreunpleasant.
Whensleepwasrestricted,peoplereportedevenmoreanger,regardlessofthenoise.”Sleeplossisknowntoincreasenegativemo
ods,suchasanxietyandsadness,anddecreasepositivemoods,suchashappinessandexcitement.However,theteamsaystheyfoundtha
tsleeplossuniquelyaffectedanger.【解题导语】本文是一篇说明文。大家都知道睡眠不足和坏情绪之间有联系,但是之前的研究都没有表明到底是睡眠不足引起了愤怒,还是愤怒引起了睡眠不足。最新的一项研究给出了答案。5.Whatdidthestud
ymentionedfindout?A.Somedisadvantagesofsleepingless.B.Somesignsofhavingpoor-qualitysleep.C.Thelinkbetwee
nlackofsleepandnegativemoods.D.Thecause-effectrelationshipbetweensleeplossandanger.D解析:细节理解题。根据第一段中的Thisisoneofthefirststudiestoprovideevid
encethatsleeplosscausesanger.以及第二段内容可知,文中提到的这项研究是发现了睡眠不足和怒气之间的因果关系。6.What’sthepurposeofaskingthevolunteerstolistentounpleasantn
oise?A.Tomakethemangry.B.Tomakethemawake.C.Totaketheirattentionaway.D.Toaffecttheirthinkingability.A解析:推理判断题。根据第四段中的Inordertomeasurean
ger和Krizansaysthepurposewastocreateuncomfortableconditions.以及后面的实验结果可推测,这个实验中的噪音主要是想提供一个令人不舒服的环境,激起志愿者们的怒气。7.FromwhatKrizansa
id,weknow________.A.thereasonsforthestudyB.thefindingsofthestudyC.theprocessofthestudyD.themethodusedinthestudyB解析:推理判断题
。从倒数第二段Krizan说的话中,我们可以知道关于这项研究的一些发现。Ⅲ七选五Airpollution,asweknowtoday,startedwiththeIndustrialRevolutioninEuropeinthe19thcent
ury.Inthelastfewdecades,ithasbecomethemajorproblemofourenvironment.1.________Itmayalsocauseharmtootherlivingthingssuchasanimalsandfoodcrops.O
urmodernlifestylehasledtodirtierairovertheyears.Factories,vehiclesofallkinds,andthegrowingnumberofpeoplearethethingsthatareresp
onsibleforairpollutiontoday.2.________Forestfiresandduststormscanalsoleadtothepollutionoftheatmosphere.Therearetwotypesofozone(臭氧
)thatweknowof.3.________Butontheground,peopleproduceozone,too.Trafficandfactoriescausegroundozone.Itisespeciallydangerousfo
rchildrenandolderpeople.4.________Choosingotherformsofenergy,likesolarenergyorwindenergycouldbehelpfulincontrollingpollution.CitieslikeLon
donhaveshownthatbetterairqualitycanbeachievedinashorttime.Smogisacombinationofsmokeandfog(雾).DuringthebeginningoftheIndustrialRevolution,thousan
dsofpeoplediedinLondoneveryyear.However,alothasbeendonetopreventsmogrecently.Factoriesusecoalthatdoesn’thavemuchharmfulmateriali
nit.Andcarsaremuchcleanertoday.5.________A.Butnotallpollutionintheairiscausedbyhumans.B.Westudentscanal
sohelpmaketheairarounduscleaner!C.Thejobofcleaningupourairisdifficultbutnotimpossible.D.Actually,naturalozoneisintheupperpartofouratmos
phere.E.Itmaycausesomeseriousdiseasesandevendeathforhumans.F.Insomecities,carsarenotevenallowedtodriveonsmogdays.G.Bothhumanactivityandnatur
alprocessescancreateairpollution.【解题导语】本文是一篇说明文。文中讲述了大气污染的危害、形成原因,以及应对它的一些方法。1.E解析:此空设于段中,与上文存在逻辑上的指代关系。本句中的It指代的是第一句中提到的Airpoll
ution。根据后一句中的Itmayalsocause...也可推出此句是要指出大气污染的一些危害。2.A解析:此空设于段中,是一个过渡句。本空前一句指出的都是由于人类的一些活动而导致的大气污染,而空格后面的F
orestfiresandduststorms都是自然灾害引起的大气污染,所以可推出此空承上启下,指出不是所有的大气污染都是由人类引起的。3.D解析:此空设于段中,是对首句的进一步解释说明。首句提出,我们所知道的有两种臭氧,此句和后一句都是对这两种臭氧的进一步解释,即天然臭氧处于大气层的上部,
而人类在地面上也会产生臭氧。4.C解析:此空设于段首,是本段的主题句。本段后面的内容都是围绕空气是可以被净化的这一说法而展开的。5.F解析:此空设于段尾,是对本段第三句的进一步具体解释。第三句提出,最近针对雾霾已经出现了很多措施,工厂用的煤含有很少的有害物质,汽车也变得更
清洁了,甚至在雾霾天,一些城市都不允许汽车出行。