Unit 4 Lesson 4 Grammar Focus (4a-4d)（讲解课件）-【优翼·学练优】2025-2026学年八年级英语下册同步备课（人教版）

该初中英语课件聚焦形容词副词比较级、最高级及大数字读法，通过对比黄河与长江、黄山与珠峰等自然奇观实例导入，搭建从具体情境到语法规则的学习支架，帮助学生衔接新旧知识。 其亮点在于结合8848.86米珠峰高度等真实数据培养语言能力，对比青海湖与贝加尔湖渗透文化意识，通过pair work和问题设计提升思维品质。学生能学以致用，教师可借助丰富实例优化教学。

Unit 4 The Wonders of Nature Section A What is amazing about nature? Grammar Focus(4a-4d) Learning Objectives In this lesson you will: 1. review the usage of the comparatives and superlatives. 2. master the rules about how to read large numbers in English. 3. talk about more natural wonders and places using the target language. Look and Say Work in pairs to compare the following natural wonders. Yellow River Yangtze River 5464km 6300km e.g.The Yangtze River is longer than the Yellow River. It’s the longest river in China. Mount Huangshan Mount Qomolangma 1,864.8 m 8,848.86 m e.g. Mount Qomolangma is the tallest mountain in the world, while Mount Huangshan is famous for its unique scenery. Sahara Desert Taklimakan Desert 9,000,000 square kilometers, in Africa 337,600 square kilometers, in China e.g. The Sahara Desert is much larger than the Taklimakan Desert and it’s the largest desert in the world. The Taklimakan Desert is the largest in China. Lake Baikal Qinghai Lake /baɪˈkæl/ salt water lake, the largest lake in China the deepest lake in the world, with a maximum depth of 1,642 meters e.g. Lake Baikal is the deepest lake in the world, while Qinghai Lake is the largest lake in China. Read the sentences. Circle the adjectives which compare things. Underline the adverbs which compare actions. 4a 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. 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. Grammar Rules 形容词和副词的比较级和最高级的构成 构成方法 原级 比较级 最高级           单音节词和部分双音节词 一般情况下，比较级词尾加-er，最高级词尾加-est。 tall short high taller shorter higher tallest shortest highest 以字母e结尾的词，比较级词尾加-r，最高级词尾加-st。 large late larger later largest latest 重读闭音节词尾只有一个辅音字母时，先双写该辅音字母，然后比较级词尾加-er，最高级词尾加-est。 big fat thin bigger fatter thinner biggest fattest thinnest 构成方法 原级 比较级 最高级  单音节词和部分双音节词 以“辅音字母+y”结尾的双音节词，先把y改为i，然后比较级词尾加-er，最高级词尾加-est。 easy heavy easier heavier easiest heaviest 多音节词和部分双音节词   词前加more构成比较级，词前加most构成最高级。   beautiful quickly   more beautiful more quickly   most beautiful most quickly 形容词和副词的比较级和最高级的用法 等级 用法 例句 比较级 表示两者(人或事物)的比较。在“比较级+than”的句型中，当than前后所使用的动词相同时，通常用助动词代替后面的动词。该助动词也可以省略。 I'm more outgoing than my sister. She sings better than he (does).  最高级 表示三者或三者以上(人或事物)的比较，其中有一个在某一方面超过其他几个，后面可用带有of、in、among的短语等来说明比较的范围。形容词最高级的前面一般要加定冠词the，副词最高级前的the可以省略。 What’s the biggest desert in China? Is that the longest river in China? Jack studies (the) hardest in his class. “as+形容词或副词原形+as”句型 (1)表示 “两者在某一方面相同时”，用“as+形容词或副词原形+as”的句型。例如: I think science is as important as maths. Tom runs as fast as Jack. (2)表示 “一方在某一方面不及另一方时”，用“not as / so+形容词或副词原形+as”的句型。例如: It is not as / so warm today as yesterday. He did not come as / so early as Wang Lin. 大数字的英文读法 英语里数字的基本单位有：hundred（百） ，thousand（千） ，million（百万） ，billion（十亿） ，trillion（万亿，兆） 。例如： 300 读作 three hundred   5000 读作 five thousand 具体数字读法： 以数字345,678,912为例: 1）从右向左划分:按照三位一节，用逗号隔开，这个数字可划分为345,678,912。从右往左，第一个逗号前是千(thousand)，第二个逗号前是百万(million)，第三个逗号前是十亿(billion) 2）依次读出每一节: 最右边一节912，读作“nine hundred and twelve”(注意，在英式英语中，百位和十位之间常用“and”连接，美式英语中，“and”可省略)。 中间一节678，读作“six hundred and seventy-eight”，加上它的单位“thousand”，这部分就读作“six hundred and seventy-eight thousand”。最左边一节345，读作“three hundred and forty-five”，加上单位“million”，这部分读作“three hundred and forty-five million"。 3）组合起来:整个数字就读作“three hundred and forty-five million, six hundred and seventy-eight thousand, nine hundred and twelve"。 注意：小数点读作“point”，小数点左边的数按整数读法读，右边的数依次读出每个数字。例如: 3.14读作“three point one four” 8848.86 读作“eight thousand，eight hundred and forty-eight point eight six" . Write or spell out the numbers. 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. 5895 25,768 four thousand three hundred and thirty-seven thousand 4b Complete the passage with the correct forms of the words in the box. 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_________and louder.Then, right before our eyes, the waterfall appeared. It went on for as ________ as the eye could see. Later, 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! largest close louder far most amazing 4c Write some questions to compare places. Then ask a partner your questions. What is the highest ...? Which park is bigger, ... or ...? 4d 1. 25,768 cubic metres of water pours down Inga Falls each second. Language Points cubic是形容词，意为“立方的” ，可以表示体积单位，还可以用来描述物体呈立方体形态。名词形式为 “cube”（立方体、立方）。 常见搭配： cubic meter 立方米（缩写：m³） cubic centimeter 立方厘米（缩写：cm³） a cubic structure 立方体结构 pour down 大量倾泻、涌下 多用来形容雨、雪、阳光等自然现象 “猛烈、持续地降下”，主语通常是自然事物（如 rain, snow, sunlight） e.g. The rain poured down all night, so the roads were flooded this morning.（雨下了一整夜，所以今早路面被淹了。） Warm sunlight poured down through the window, lighting up the room.（温暖的阳光透过窗户洒进来，照亮了整个房间。） 本文件著作权为创作公司所有, 仅限于教师教学及其他非商业性和非盈利性用途。如发现盗用、转卖、网络传播等侵权行为, 本公司将依法追究其相应法律责任。 部分素材选自网络, 如有争议, 请联系删改。 声 明 $