八年级英语te-earth’s-atmosphere课件.pptVIP

本单元的重点知识： 1. 单词：熟练掌握本单元后单词的音、形、意 2. 词组： 1) be made from 由……制造 2) be made of 由……制造 3) tiny drops of water 小水滴 4) reduce waste 减少浪费 5) 20 miles thick 20英里厚 6) protect…from 保护……免遭…… 7) be made up of 由……组成 8) three—fourths of the gases 3/4的气体 9) depend on 依靠 10) stay alive 生存 11) be used to 习惯于 12) draw worldwide attention 吸引世界注意 13) blow…away 吹走 14) be full of 充满…… 15) be used for 用于做某事 句子： 1) Clouds are made of tiny drops water. 云是由小水滴构成的。 2) The atmosphere surrounds the earth like a blanket. 大气层像毯子一样包裹着地球。 3) The atmosphere protects the earth from the sun’s heat. 大气层保护地球免遭太阳的炙烤。 4) The air in the atmosphere is made up of dust and gases. 大气层中的空气是由尘土和各种气体组成。 5) More than three-fourths of gas is nitrogen. 多于四分之三的气体是氮气。 6) Plants depend on nitrogen to stay alive. 植物依靠氮气来生存。 7) More than three-fourths of the gas is nitrogen. 气体中四分之三的气体都是氮气。 8) People who travel to the mountains find it harder to breathe. 到山上旅行的人发现这里呼吸比较困难。 9) Big cities are full of cars. 大城市里都是汽车。 10) They are used for business and pleasure. 他们是用来商务和娱乐的。 11) Something should be done about the use of cars in order to have cleaner air. 为了得到更清洁的空气，应该就汽车的使用问题采取措施。 六、本单元重点知识讲解： 1. The ship is made from waste materials. The T-shirt is made of cotton. 例如： ① The book is made of paper and paper is made from wood. ② The glass is made of glass and glass is made from SiO2. 2. The air that surrounds the earth is called the atmosphere. 包围地球的空气被称为大气。 be called 被称为 同义词：be named 例如： The boy is called “Da Niu” by his classmates. The machine is called “Washing machine”. That city will be called “Water City”. 3. It surrounds the earth like a blanket—20 miles thick. 20 miles thick 20英里厚 数字+单位+形容词 例如： 1.7 metres tall 一米七高 6 metres wide 六米宽 20 kilometres away 20公里远 ① Our classroom is three metres tall, 7 metres long and 6 metres wide. ② The Yellow River is 5000 kilometres long. It is the second longest river in China. ③ The river is about 20 metres deep. You mustn’t swim in it