Howlifebeganontheearth

1、vUnit 4vAstronomy: the science of vthe stars1. To learn the basic knowledge about astronomy. 2. To learn more knowledge about how life began on the earth.3. To summarize and remember the main idea of the passage.ObjectivesvWhat do you know about astronomy?vIs there life on the planet?八大行星八大行星你知道吗？你知

2、道吗？Mercury(水星）水星）Venus（金星）（金星）Mars（火星）（火星）Jupiter(木星木星)Uranus(天王星）天王星）Saturn(土星土星)Neptune(海王星）海王星）Earth（地球）（地球）THE SOLAR SYSTEM Can you name each planet correctly using the letters given in the table below? A.地球地球 _B. 木星木星 _C.火星火星 _D.水星水星 _E. 海王星海王星 _F. 冥王星冥王星 _G. 土星土星 _H. 天王星天王星 _I. 金星金星 _EarthJupi

3、terMarsMercuryNeptunePlutoSaturnUranusVenus你记住了吗？你记住了吗？八大行星八大行星 八大行星即金星、土星、木星、水星、地球、火星、天王星、海王星八颗行星，冥王星不再为经典行星。 国际天文学联合会大会投票5号决议，部分通过新的行星定义，冥王星被排除在行星行列之外，而将其列入“矮行星”。 新的天文发现不断使“九大行星”的传统观念受到质疑。天文学家先后发现冥王星与太阳系其他行星的一些不同之处。冥王星所处的轨道在海王星之外，属于太阳系外围的柯伊伯带，这个区域一直是太阳系小行星和彗星诞生的地方。20世纪90年代以来，天文学家发现柯伊伯带有更多围绕太阳运行的大天

4、体。比如，美国天文学家布朗发现的“2003UB313”，就是一个直径和质量都超过冥王星的天体。八大行星（续）八大行星（续） 国际天文学联合会大会放弃将冥王星之外的太阳系八大行星称为“经典行星”的说法，从而确认太阳系只有8颗行星，冥王星被降级为入“矮行星”。此前盛传的第一种方案中提出了太阳系另外增加3颗二级行星的计划流产。Big BangHow life began on the earth?宇宙大爆炸 大约在50亿年前，宇宙所有的物质都高度密集在一点，有着极高的温度，因而发生了巨大的爆炸。大爆炸以后，物质开始向外大膨胀，就形成了今天我们看到的宇宙。大爆炸的整个过程是复杂的，现在只能从理论研究的

5、基础上描绘过去远古的宇宙发展史。在这150亿年中先后诞生了星系团、星系、我们的银河系、恒星、太阳系、行星、卫星等。现在我们看见的和看不见的一切天体和宇宙物质，形成了当今的宇宙形态，人类就是在这一宇宙演变中诞生的。Do you know how our life began on the earth? Do you know any ancient idea about the beginning of the universe? Pangu separates the sky from the earthNvwa makes human beingsThe development of lif

6、eThe development of lifeHOW LIFE BEGAN ON THE EARTH?How life began on the earth Big Bang A solid ball The earth Atmosphere It was full of water.Original cellsThe cells in the water began to separate.waterplants in the watershellfish and fishplants on landinsects and amphibiansmammals reptiles dinosa

7、urs Analysing How life began on the earthwatergreen plants on landforests1. small plants in water2. shellfish and all sorts of fish3.4.insects (on land)amphibians (on land and in water)reptiles (on land)dinosaurs (on land)mammals (on land) small clever animals with hands and feet human5.6.7.8.reptil

8、es (on land)dinosaurs (on land)mammals (on land) small clever animals with hands and feet humanParagraph 1Paragraph 2Paragraph 3Paragraph 4Paragraph 5Main BodyA widely accepted theory about the formation of the universeThe formation of the earthThe importance of water for lifeThe development of plan

9、ts and animals on the earthThe arrival of humans and their impact on the earth Answer the following questions: 1. About how the universe began, which theory is widely accepted? 2. What form（形状） was the earth after the “Big Bang”? 3. What made up the earths atmosphere after the earth exploded?Para. 1

10、&2: the formation of the universe and the earthPara. 3 the importance of water for lifevWhat made the earth different from the other planets is that water remained on the earth.vThe significance(意义) of the continued presence of water is that it allowed the earth to dissolve harmful gases and aci

11、ds into the oceans and seas. 1. Small plants in water2 .Shellfish and all sorts of fish3. Green plants on land4. Insects (on land)5. Amphibians (on land and in water)6. Forests7. Reptiles (on land)8. Dinosaurs (on land)9. Mammals (on land)Para. 4 The development of lifePara. 5 the arrival of humans

12、and their effects on the earth Answer the following questions: 1. What problems have been caused by humans to the earth? 2. What does the last sentence mean?找出课文中能够说明地球上生命的起源以及进化的词语或句子1.2.6.3.4.5.7.8.9.Small plants in waterShellfish and all sorts of fishGreen plants on landInsects (on land)Amphibian

13、s (on land and in water)forestsReptiles (on land)Dinosaurs (on land)Mammals (on land)Put the order of development of life into a timeline. vInsects and amphibians appeared.vThe earth became a solid ball.vReptiles appeared.vThe earth was a cloud of dust.vShellfish and other fish appeared.vClever anim

14、als with hands and feet appeared.vDinosaurs appeared.vSmall plants grew on the water.vPlants began to grow on dry land.vWater appeared on the earth.vThe universe began with a “Big Bang”.vMammals appeared.Keys: 10 7 3 8 4 9 6 1 5 2 12 11Discussion: Some scientists have found that there is water on Mars. 1.Can