Unit 4 The Wonders of Nature第4课时（Section A 4a-4d）(课件)2025-2026学年人教版英语八年级下册

Unit 4 The Wonders of Nature 第4课时 (Section A 4a-4d) R·八年级下册 Review What is the ________ desert in the world? It’s the Sahara Desert. biggest Look and fill in the blanks. the Sahara Desert It’s about __________square kilometres in size. How big is it? 9,000,000 the Sahara Desert Where is the _______ point in the ocean? It’s in the Mariana Trench. deepest It’s about _______ metres deep. How deep is it? 11,000 What are the deep- sea animals like? Some animals are blind, but they can “see” as ____ as others. well Mount Qomolangma is one of the _______ wonders of the world, and it is still growing ______. greatest taller The Yangtze River travels the _______ in China and is about 6,300 kilometres long. farthest What is the biggest desert in the world？ It is the Sahara Desert. How big is it？ It is about 9,000,000 square kilometres in size. Where is the deepest point in the ocean？ It is in the Mariana Trench. How deep is it？ It is about 11,000 metres deep. Read the sentences. Circle the adjectives which compare things. Underline the adverbs which compare actions. 4a 比较 Some deep-sea animals are blind, but they can “see” as well as others. Mount Qomolangma is one of the greatest wonders of the world, and it is still growing taller. The Yangtze River travels the farthest in China and is about 6,300 kilometres long. What is the biggest desert in the world? Where is the deepest point in the ocean? Some deep-sea animals are blind, but they can “see” as well as others. Mount Qomolangma is one of the greatest wonders of the world, and it is still growing taller. Let’s think 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→ lowest deep→ deeper→ deepest wise→ wiser→ wisest simple→ simpler→ simplest lonely→ lonelier→ loneliest happy→ happier→ happiest hot→ hotter→ hottest big→ bigger→ biggest interesting→ more interesting → most interesting carefully→ more carefully →most carefully 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/well bad/badly/ill little many/much far better worse less more father/further best worst least most farthest/ 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……”。 The Sahara Desert is larger than the Gobi Desert. 撒哈拉沙漠比戈壁沙漠更大。 The cheetah can run faster than the tiger. 猎豹能比老虎跑得更快。 (2) “A+谓语动词+比较级+than any other+ 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。 Lake Baikal is deeper than any other freshwater lake in the world. =Lake Baikal is the deepest freshwater lake in the world. 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……”。 The higher you climb a mountain, the thinner the air becomes. 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“more and more+形容词/副词原级”结构。 Because of climate change, our earth is getting warmer and warmer. 由于气候变化，我们的地球正变得越来越暖和。 The Internet is becoming more and more important in our daily life. 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+of the two...”意为“……是两者之中较……的那个”，是特指的情况。 Amy is the taller of the two girls. 埃米是两个女孩中较高的那个。 (6) “Who/Which+谓语动词+比较级, A or B?” 表示两者之间进行比较，意为“谁/哪一个更……，A还是B？”。 Which waterfall is larger, the Hukou Waterfall or the Huangguoshu Waterfall? 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-speed trains are much faster than traditional ones. 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……”。 The sweater is a little bit short. Pass me a longer one, 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，a lot，a little，a bit，even，far等修饰，用来加强语气或表示程度。 The river is much deeper than that one. 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…… Greenland is the biggest island in the world. 格陵兰岛是世界上最大的岛屿。 (2) one of the+形容词最高级+可数名词复数 最……的……之一 It is one of the busiest streets in our town. 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…… Sam is the second tallest boy in his class. 萨姆是他们班第二高的男生。 (4) Who/Which+谓语动词（+the）+最高级，A，B or C? 在A、B 和C中，谁/哪一个……最……？ Which season is the most beautiful, spring, summer or autumn? 春天、夏天和秋天中，哪个季节最美？ Who jumps highest, Tom, Jim or Mike? 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。 This movie is (the) most exciting. 这部电影最刺激。 （2）副词最高级前的the一般可以省略。 Lucy dances (the) best of all the girls. 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’s best friend is from Canada. 汤姆最好的朋友来自加拿大。 This is my youngest brother. 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+than any other+单数名词”或“比较级+than the other+复数名词”进行转换。 Tom is the youngest student in his class. =Tom is younger than any other student in his class. =Tom is younger than the other students in his class. 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. My father is much ________ (heavy) than me. 2. The scientists found one of the _________ (tall) trees in the world. 3. This ancient bridge is the third _________ (old) building in our hometown, with a history of over 100 years. heavier tallest oldest 专项演练 4. Qinghai Lake is _________ (large) than any other salt lake in China. 5. When Helen won a prize in the English competition, she believed she was the _________(happy) girl in the world. larger happiest Let’s think 试着读出画横线部分的大数字？你能发现什么规律？ How big is it? It is about 9,000,000 square kilometres in size. How deep is it? It is about 11,000 metres deep. The Yangtze River travels the farthest in China and is about 6,300 kilometres long. 读作：nine million 读作：eleven thousand 读作：six thousand and three hundred 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： 5,764 five thousand, seven hundred and sixty-four 265,468 two hundred and sixty-five thousand, four hundred and sixty-eight 19,357,095 nineteen million, three hundred and fifty-seven thousand, and ninety-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（ten thousand）” 表示，“十万”用“百个千（one hundred thousand）”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。 The number “23,456” can be read as“________”． A. twenty-three thousand, four hundred and fifty-six B. twenty-three thousand and four hundred fifty-six C. two three thousand and four five six D. two three thousand, four and five six Write or spell out the numbers. 4b 1.Mount Kilimanjaro is________ (five thousand, eight hundred and ninety-five) metres high. 2.__________ (twenty-five thousand, seven hundred and sixty- eight) cubic metres of water pours down Inga Falls each second. 3.The East African Rift Valley is about 4,000 (______________) miles long. 4.The Taklimakan Desert has a total area of about 337,000 (__________________________________) square kilometres. 5, 895 three hundred and thirty-seven thousand 25, 768 four thousand 乞力马扎罗山 倾泻而下 英加瀑布 东非大裂谷 ……总面积为…… Complete the passage with the correct forms of the words in the box. 4c large amazing far close loud My friends and I visited Victoria Falls in Africa last year. Visiting one of the world’s _________ waterfalls was a magical experience. As we went _________ to the falls, the noise of the water slowly grew louder and _________. Then, right before our eyes, the waterfall appeared. It went on for as _______ as the eye could see. Later, large amazing far close loud 维多利亚瀑布 largest closer go close to 靠近；接近 louder 就在眼前；眼皮底下 far as far as the eye can see 极目所尽 we sat in a special pool at the top of the falls. There, we felt the water rush past us and become a part of the waterfall. It was the scariest but also the _____________ experience of our trip! large amazing far close loud most amazing Write some questions to compare places. Then ask a partner your questions. 4d What is the highest...? Which park is bigger, ... or ...? 疑问词（组）+谓语动词+比较级，A or B? A和B，……更……？ A: What is the highest tower in China? B: It’s the Shanghai Tower. A: Which park is bigger, Hyde Park or Greenwich Park? B: Hyde Park. A: What’s the deepest lake in the world? B: It’s Lake Baikal. A: Which river is longer, the Yangtze River or the Nile River? B: The Nile River. 活动示范 Homework Review the grammar of this lesson. Do some related exercises. $