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1、人教课标 高一 必修 3 Unit 4HOW LIFE BEGAN ON THE EARTHWarming upWhat are the names of the eight planets that circle our sun?海王星 Neptune水星Mercury 金星Venus 地球Earth 火星Mars 木星Jupiter 土星Saturn天王星Uranus 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
2、years D. About 6.5 billion years 2. _ of the earth surface is covered by water. A. 20% B. 30% C. 50% D. 70%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.
3、About 6.5 billion5. 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
4、8. Which 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 C. Russia D. U.S.APrediction Look at the picture. Do you know the topic of this unit?海洋里的细胞开始分裂 登陆爬行动物恐龙Mammals人类的兴起Do you know w
5、hat it was like before life appeared on earth?可以演化成低级生命的小液滴水泡状的太空原始生命体It was full of water.1. What do we mean when we say we are studying a subject scientifically? Or whats the correct attitude towards science? We should be objective, not superstitious.2. Whats the correct way to prove a scientific
6、idea? We should design experiments to test it for several times. Then we can analyze the results and draw a conclusion at last.3. What are the most important skills we need to be real scientists? Careful, objective and logical, draw conclusions from the experiments and not impose conclusions on the
7、data. (impose on 把强加于)1. The origin of life on earth is a question that interests astronomers. What do you know about it? How old is the universe? (several billion years ago) How old is the Earth? (between 4.5 and 3.8 million years ago) Which were the first creatures or plants on Earth?.Pre-reading2
8、. Each religion and culture has its own ideas about how life began on earth. What do you know? In China, we all know that Pangu separates the sky from the earth and Nvwa made humans.Pangu separates the sky from the earth. 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
9、, 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。Nvwa made humans.Other legends about the beginning of universe.The Biblical AccountDay 1: God spoke and separated light from darkness creating Day and Night. Day 2: God spoke and separated the water creating sky
10、and ocean. Day 3: God spoke and created dry land. Day 4: God spoke and created the sun, moon and stars. Day 5: God spoke and created living creatures in the air and sea. Day 6: God spoke and created the land animals and man. Day 7: God rested and blessed this day calling it Holy. India Brahma is the
11、 god first represented in the Hindu Triad. He is the creator of the universe and all living beings are said to have evolved from him. Big BangGasNew starsDying starsremnants平面图 太阳系地球大气1. When did the “Big Bang” happen? It happened several billion years ago.Scanning Read the passage quickly and answe
12、r the questions.2. What form was the earth after the “Big Bang”? The earth was still just a cloud of dust.3. What made up the earths atmosphere after the earth exploded? Carbon, nitrogen, water vapour and other gases. 4. How did water come into being on the earth? As the earth cooled down after it e
13、xploded, water came into being.5. Whats the significance of the presence of water on the earth? It allowed the earth to dissolve harmful gases and acids into the oceans and seas.6. What was important to the development of fish? oxygen. 7. What made possible the rise of mammals on the earth? The disa
14、ppearance of dinosaurs made the possible the rise of mammals on the earth.8. Why are mammals different from all life forms in the past? They gave birth to young baby animals and produced milk to feed them.Careful readingI. Read the passage carefully and match the main idea with each paragraph. Para.
15、 1 The formation (形成) of the earth.Para. 2 The importance of water for life.Para. 3 A widely accepted theory about the formation of the universe.Para. 4 The arrival of humans and their impact on the earth. Para. 5 The development of plants and animals on the earth.II. Answer the following questions.
16、1. Why was the earth different from other planets? The water remained.2. Why did the plants grow before the animals came? Because plants provide oxygen for animals to breathe. 3. Why is it wrong in films and stories to show dinosaurs and people together? Because dinosaurs died out long before human
17、beings developed on the earth.4. Why do you think that humans are the cleverest animals on the earth? They are the cleverest animals because they have larger brains than any other creature on the earth so far.5. There used to be nine planets in the solar system. Recently scientists have decided that
18、 one of them can no longer be considered a planet. Do you know the name of that planet? Do you know why they removed it? Pluto. Scientists now think it is too small to be called a planet. 6. What problem is caused by human beings? They cause global warming. III. Fill in the blanks in the following f
19、orm.TimeWhat happenedBig Bang _ began to form and combine to create stars and other bodies.AtomsBetween 4.5 and 3.8 billion years ago Dust settled into a solid and _ globe. The earth exploded to produce its _. The continued _ of water allowed the earth to dissolve harmful gases and _ into the oceans
20、 and seas.violentatmospherepresenceacidsMany millions of years later The first small plants on the surface of the water produced _. Early _ and all sorts of fish appeared. Green plants began to grow on land. Insects and _ appeared.oxygenshellfishamphibiansMany millions of years later _ appeared and
21、they laid eggs. Dinosaurs developed, laid eggs and _ for more than 140 million years. Mammals rose and _ babies.Reptilesexistedgave birth toAbout 2.6 million years ago Some small _ animals with hands and feet appeared and spread all over the earth.NowHumans produce too much carbon _, making the eart
22、h too hot.cleverdioxideIV. True (T) or False (F).1. The earth appeared before the Big Bang happened.2. The original atmosphere consisted of nitrogen and oxygen. 3. The main difference between the earth and other planets is that there is water on the earth. 4. Life began in water and then on land.FFT
23、T5. Mammals appeared before the development of dinosaurs.6. Dinosaurs could give birth to young baby animals and produced milk to feed them. 7. Human beings produce too much carbon dioxide which causes the global warming on the earth. 8. According to the text, human beings would disappear in the end
24、. FFTFHow life began on the earth.“Big Bang”other bodies_ starsEarth: a cloud of _atomsdustSummary a solid _the earths _other _Water: _ to the development of lifewater vapour nitrogen carbonextremely small _ on the surface of the waterglobegasesatmospherefundamentalplantsearly _ and all sorts of fis
25、hgreen plants on landland animalsinsectsamphibians_huge animals (dinosaurs)the rise of _human beingsshellfishreptilesmammalsWe have We have only one only one earth!earth!Speaking What should we do for our earth?You can use the following words or phrases to help you:prevent from harmful global warmin
26、g carbon dioxide in turn depend on as a result thus atmosphereWhat should we do for our earth?Lets take part in the activities to save the earth!How life began on earth is one of the biggest puzzles that scientists found hard to solve. What other puzzles are hidden in the passage? Find them out and do some research.