2024新版2026春人教版英语八年级下册教学课件：Unit4 第4课时（Section A 4a-4d）

Unit4TheWondersofNature第4课时(SectionA4a-4d)R·八年级下册ReviewWhatisthe________desertintheworld?It’stheSaharaDesert.biggestLookandfillintheblanks.theSaharaDesertIt’sabout__________squarekilometres

insize.Howbigisit?9,000,000theSaharaDesertWhereisthe_______pointintheocean?It’sintheMarianaTrench.deepestIt’sabout_______metresdeep.Howdeepisit?11,000Whatarethedeep-seaanimalslike?Someanimalsareblind,buttheycan“see”as____asothers.wellMountQomolangmaisoneofthe_______wondersoftheworld,anditisstillgrowing______.greatesttallerTheYangtzeRivertravelsthe_______inChinaandisabout6,300kilometreslong.farthestWhatisthebiggestdesertintheworld？ItistheSaharaDesert.Howbigisit？Itisabout9,000,000squarekilometresinsize.Whereisthedeepestpointintheocean？ItisintheMarianaTrench.Howdeepisit？Itisabout11,000metresdeep.Readthesentences.Circletheadjectiveswhichcomparethings.Underlinetheadverbswhichcompareactions.4a比较Somedeep-seaanimalsareblind,

buttheycan“see”aswellasothers.MountQomolangmaisoneofthegreatestwondersoftheworld,

anditisstillgrowingtaller.TheYangtzeRivertravelsthefarthestinChinaandisabout6,300kilometreslong.Whatisthebiggestdesertintheworld?Whereisthedeepestpointintheocean?Somedeep-seaanimalsareblind,

buttheycan“see”aswellasothers.MountQomolangmaisoneofthegreatestwondersoftheworld,

anditisstillgrowingtaller.Let’sthink

最高级在对比两者或两者以上的事物时，运用了形容和副词的哪几种形式？原级比较级语法回顾英语中的形容词和副词常用三种形式来表达事物的等级差别，即原级、比较级和最高级。概述形容词和副词的比较级和最高级构成（1）规则变化构成方法示例单音节词和部分双音节词多音节词和部分双音节词low→lower→lowestdeep→deeper→deepestwise→wiser→wisestsimple→simpler→simplestlonely→lonelier→loneliesthappy→happier→happiesthot→hotter→hottestbig→bigger→biggestinteresting→moreinteresting→mostinterestingcarefully→morecarefully→mostcarefully一般情况下，在词尾加-er或-est以字母e结尾的词，在词尾加-r或-st以“辅音字母+y”结尾的词，先把“y”变为“i”，再加-er或-est以一个辅音字母结尾的重读闭音节词，双写该辅音字母，再加-er或-est在词前加more或most（2）不规则变化原级比较级最高级good/wellbad/badly/illlittlemany/muchfarbetterworselessmorefather/furtherbestworstleastmostfarthest/furthest比较级的用法形容词与副词的比较级常用于两者之间的比较，表示两者之间的差异。常用结构如下：(1)“A+谓语动词+比较级+than+B”

用于两者间的比较，意为“A比B更……”。TheSaharaDesertislargerthantheGobiDesert.撒哈拉沙漠比戈壁沙漠更大。Thecheetahcanrunfasterthanthetiger.

猎豹能比老虎跑得更快。(2)“A+谓语动词+比较级+thananyother+B（可数名词单数）”用于同一范围内的比较，意为“A比其他任何一个B都……”，表示最高级的含义。LakeBaikalisdeeperthananyotherfreshwaterlakeintheworld.=LakeBaikalisthedeepestfreshwaterlakeintheworld.贝加尔湖是世界上最深的淡水湖。(3)“the+比较级…,the+比较级…

”意为“越……，越……”。Thehigheryouclimbamountain,thethinnertheairbecomes.你爬山爬得越高，空气就变得越稀薄。(4)“比较级+and+比较级”意为“越来越……”。当形容词或副词为多音节词或部分双音节词时，用“moreandmore+形容词/副词原级”结构。Becauseofclimatechange,ourearthisgettingwarmerandwarmer.由于气候变化，我们的地球正变得越来越暖和。TheInternetisbecomingmoreandmoreimportantinourdailylife.互联网在我们的日常生活中变得越来越重要。(5)“主语+谓语动词+the+比较级+ofthetwo...”意为“……是两者之中较……的那个”，是特指的情况。Amyisthetallerofthetwogirls.埃米是两个女孩中较高的那个。(6)“Who/Which+谓语动词+比较级,

AorB?”表示两者之间进行比较，意为“谁/哪一个更……，A还是B？”。Whichwaterfallislarger,theHukouWaterfallortheHuangguoshuWaterfall?哪个瀑布更大，壶口瀑布还是黄果树瀑布？（1）比较的对象必须一致，为避免重复，常用that/one或those/ones代替前面的名词。High-speedtrainsaremuchfasterthantraditionalones.高速列车比传统的列车快很多。（2）在上文意思明确的情况下，可以单独使用“a/an+比较级+one”，意为“又一/再一更……的……”。Thesweaterisalittlebitshort.Passmealongerone,please.这件毛衣有点短。请递给我一件长点的。（3）比较级前可用much，alot，alittle，abit，even，far等修饰，用来加强语气或表示程度。Theriverismuchdeeperthanthatone.这条河比那条河深得多。最高级的用法形容词与副词的最高级常用于三者或三者以上的人或物之间的比较。常用结构如下：(1)

the+最高级+in/of...……中最……Greenlandisthebiggestislandintheworld.格陵兰岛是世界上最大的岛屿。(2)

oneofthe+形容词最高级+可数名词复数最……的……之一Itisoneofthebusieststreetsinourtown.它是我们镇上最繁忙的街道之一。(3)主语+谓语动词+the+序数词+形容词最高级+名词+in/of...……在……中是第……的……Samisthesecondtallestboyinhisclass.萨姆是他们班第二高的男生。(4)

Who/Which+谓语动词（+the）+最高级，A，BorC?在A、B和C中，谁/哪一个……最……？Whichseasonisthemostbeautiful,spring,summerorautumn?

春天、夏天和秋天中，哪个季节最美？Whojumpshighest,Tom,JimorMike?汤姆、吉姆和迈克中，谁跳得最高？（1）形容词最高级作表语时，the有时可省略。Thismovieis

(the)mostexciting.这部电影最刺激。（2）副词最高级前的the一般可以省略。Lucydances

(the)bestofallthegirls.露西在所有女孩中跳舞跳得最好。（3）最高级前有名词所有格或物主代词时，不再用the。Tom’sbestfriendisfromCanada.汤姆最好的朋友来自加拿大。Thisismyyoungestbrother.这是我最小的弟弟。试着翻译下面的句子最高级与比较级之间的转换形容词与副词的最高级可与“比较级+thananyother+单数名词”或“比较级+thantheother+复数名词”进行转换。Tomistheyoungeststudentinhisclass.=Tomisyoungerthananyotherstudentinhisclass.=Tomisyoungerthantheotherstudentsinhisclass.汤姆是他班里最小的学生。用括号内所给单词的适当形式填空。1.Myfatherismuch________(heavy)thanme.2.Thescientistsfoundoneofthe_________

(tall)treesintheworld.3.Thisancientbridgeisthethird_________(old)buildinginourhometown,

withahistoryofover100years.heaviertallestoldest专项演练4.QinghaiLakeis_________

(large)thananyother

saltlakeinChina.5.WhenHelenwonaprizeintheEnglishcompetition,

shebelievedshewasthe_________(happy)girlin

theworld.largerhappiestLet’sthink

试着读出画横线部分的大数字？你能发现什么规律？Howbigisit?Itisabout9,000,000squarekilometresinsize.Howdeepisit?Itisabout11,000metresdeep.TheYangtzeRivertravelsthefarthestinChinaandisabout6,300kilometreslong.读作：ninemillion读作：eleventhousand读作：sixthousandandthreehundred大数字的表达与读法大于1000的基数词的表达法：从右至左数，每三位数加一个逗号（即以此把数字分为若干段）。第一个逗号前的数为thousand（千），第二个逗号前的数为million（百万），第三个逗号前的数为billion（十亿）。语法新学示例如下：5,764fivethousand,sevenhundredandsixty-four265,468twohundredandsixty-fivethousand,fourhundredandsixty-eight19,357,095nineteenmillion,threehundredandfifty-seventhousand,andninety-five（1）英语没有“万”这个单位，要表示“万”须借用thousand，如“一万”用“十个千（tenthousand）”表示，“十万”用“百个千（onehundredthousand）”表示。（2）在hundred后通常加上连词and。若读数中百位数为0，则在thousand后加and。Thenumber“23,456”canbereadas“________”．A.twenty-threethousand,

fourhundredandfifty-sixB.twenty-threethousandandfourhundredfifty-sixC.twothreethousandandfourfivesixD.twothreethousand,fourandfivesixWriteorspelloutthenumbers.4b1.MountKilimanjaro

is________(fivethousand,eighthundredandninety-five)metreshigh.2.__________(twenty-fivethousand,sevenhundredandsixty-eight)cubicmetresofwaterpoursdownIngaFallseachsecond.3.TheEastAfricanRiftValleyisabout4,000(______________)miles

long.4.TheTaklimakanDeserthasatotalareaofabout337,000(__________________________________)squarekilometres.5,895three

hundred

and

thirty-seven

thousand25,768four

thousand乞力马扎罗山倾泻而下英加瀑布东非大裂谷……总面积为……Completethepassagewiththecorrectformsofthewordsinthebox.4clargeamazingfarcloseloudMyfriendsandIvisitedVictoria

FallsinAfricalastyear.Visitingoneoftheworld’s_________waterfallswasamagicalexperience.Aswewent_________tothefalls,thenoiseofthewaterslowlygrewlouderand_________.Then,rightbeforeoureyes,thewaterfallappeared.Itwentonforas_______astheeyecouldsee.Later,largeamazingfarcloseloud维多利亚瀑布largestclosergocloseto靠近；接近louder就在