unit how life began on the earthreadingPPT课件

1、海王星海王星 Saturn Saturn 水星水星Uranus Uranus 金星金星Venus Venus 地球地球Earth Earth 火星火星Mars Mars 木星木星Mercury Mercury 土星土星Jupiter Jupiter 天王星天王星Neptune Neptune 第1页/共44页A Quiz Game 1. How old is the earth? A. About 3.5 billion years B. About 4.5 billion years C. About 5.5 billion years D. About 6.5 billion years

2、2. _ of the earth surface is covered by water. A. 20% B. 30% C. 50% D. 70%第2页/共44页3. How many planets are there in the Solar System? A. 6 B. 7 C. 8 D. 9 4. What is the total population of humans on the earth? A. About 3.5 billion B. About 4.5 billion C. About 5.5 billion D. About 6.5 billion第3页/共44页

3、5. How long does the rotation (自转) of the earth take? A. 12 hours B. 24 hours C. a month D. 365 days6. Which continent is the smallest? A. Africa B. North America C. South America D. Oceania 7. On what day is the Earth day celebrated? A. April 22 B. May 4 C. August 21 D. November 11第4页/共44页8. Which

4、ocean is the largest? A. The Pacific Ocean B. The Arctic Ocean C. The Indian Ocean D. The Atlantic Ocean9. Which country has the largest area? A. Canada B. China 第5页/共44页Step 2 Pre-reading1. How did the universe begin?2. How did life begin on the earth? There are different legends(传说) of how the uni

5、verse and life began in different cultures: In Chinese culture第6页/共44页Pangu separates the sky from the earth. 第7页/共44页 中国神话传说中有盘古开天地的说法。巨人盘古用一把利斧劈开混沌, 将天地分开。死后, 他的气息化成风和云, 声音变成轰轰的雷声, 左眼化为太阳, 右眼化为月亮, 手足与四肢变成大地的四极与五方的名山, 血液化成江河,筋脉铺成道路, 肌肉形成田地, 须发成为星星, 牙齿和骨骼化为金属、珍珠、玉石, 汗水成为滋润万物生长的甘霖和雨露。第8页/共44页Nvwa mad

6、e humans.第9页/共44页In western culture: God created the world in seven days第10页/共44页Do you know what a scientific idea is?1. The universe began from the Big Bang. 第11页/共44页2. Life first began in the sea on the earth. 第12页/共44页3. Life was brought to the earth by ET from outer space. 第13页/共44页Whats the w

7、riting style of the text?A. Narrative 记叙文B. Explanation 说明文C. Essay 散文第14页/共44页 1. Whats the main idea of the text? 2. How many parts can the text be divided into? Whats the main idea for each part?Step 3: ReadingFast-reading第15页/共44页Para.1 Para.2Para.3Para.4Para.5A_ about how the universe was forme

8、dThe_ of the earthThe importance of_ for lifeThe_ of plants and animalsThe arrival of _ and their effects on the earththeoryformationwaterdevelopmenthumansHow life began on the earth第16页/共44页Lets get to know how life began on the earthTask two: Read paragraph 1-3 quickly by yourselves.After the “Big

9、 Bang”,what happened on the earth ?第17页/共44页1. Who knows how life began on the earth exactly?A. Scientists. B. Astronomers.C. No one. D. Aliens (外星人外星人).2. Why was the earth different from other planets?A. It produced a lot of heat. B. The water remained.C. Water disappeared. D. It was the oldest pl

10、anet.第18页/共44页3. Why was life able to develop on the earth but not on other planets?A.The earth had a solid shape. B. The earth did not have harmful gases in its atmosphere. C. The water stayed on the earth but not on other planets. D. The earth was not too hot and not too cold.第19页/共44页Stage 1: The

11、 development of the earth(1) After the Big Bang, what happened? a cloud of dust a violent solid ball 第20页/共44页exploded with fire and rock Produced carbon,nitrogen, water vapor and gases(2) What happened next?第21页/共44页(3) What did water vapour and gases make?the earths atmosphere第22页/共44页Water appear

12、ed which is important for the beginning of life on the earth. (4) What appeared on the earth then?第23页/共44页(5) What did the water form?oceans and seas第24页/共44页retell how the earth and water come aboutBig BangA cloud of dustA solid globeExploded loudly with fire and rockcarbon, nitrogen, water vapor

13、and other gasesthe earths atmosphereThe earth cooled downWater appeared第25页/共44页Read paragraph 4 and 5 quickly, and find out the order of development of life on the earth第26页/共44页arrival of small plants in waterWhat life developed after water appeared?early shellfish and all sorts of fishStage 2: Th

14、e development of life in water第27页/共44页Stage 3: The development of life on land.green plants on land insects on landamphibians on land and in the water(1) What life developed after the life in water?第28页/共44页 reptiles on land dinosaurs on land(2) What life developed after forests appeared? How do re

15、ptiles produce young? by laying eggs第29页/共44页mammals on land(3) What life developed after dinosaurs? How do mammals produce young? by giving birth to baby animals and producing milk to feed them.第30页/共44页 humans came into beingStage 4: The development of humans What life developed after mammals?第31页

16、/共44页They developed new methods of growing food, hunting,and moving around. 1. What did humans develop?They are putting too much carbon dioxide into the atmosphere.2. What problem are humans causing?第32页/共44页 Step 4 Comprehending1. Why was the earth different from other planets? 2. Why was life able

17、 to develop on the earth but not on other planets? 3. Why was it necessary for plants to grow before animals? 4. What problem is caused by human beings? The water remained.The earth did not have harmful gases in its atmosphere.Plants provided oxygen for animals to breathe.They cause global warming.第

18、33页/共44页According to the pictures, have a try to retell the development of life.第34页/共44页第35页/共44页第36页/共44页Put the order of development of life into a time line.A. insects and amphibians appearB. a solid ballC. reptiles appear D. a cloud of dustE. shellfish and other fish appearF. dinosaurs appear G. small plants grow on the waterH. plants begin to grow on dry landI. presence of waterJ. mammals (including humans )appearDBIGEHACFJ第37页/共44页Discussion Why is it wrong in films and stories to show dinosaurs and people together?Dinosaurs died out long before human