2. Unit 4 Reading How Life Began On The Earth

3. Leading-in This unit is concerned with astronomy and how human beings first evolved on the earth and understand the universe around them. There are many different stories that tell how universe began. There are three statements of the origin of life.

4. Leading-in 1 ．神造说 (God made) 这一假说认为地球上的各种生物都 是由神创造出来的，生命是上帝或神按照一定的目的， 一次性地创造出来的。 2. 宇宙生命论 (Life in the universe) 这一假说提倡 “ 一切 生命来自生命 ” 的观点，认为地球上最初的生命来自宇 宙间的其他星球，即 “ 地上生命，天外飞来 ” 。 3. 非生命物质 (Non-living material) 地球上原本没有生命， 生命起源于非生命物质。宇宙大爆炸 (Big Bang ) 后， 地球只是一团尘埃，然后形成固体球状。经过后期的动 荡，球体爆炸喷出烈火与岩石，并释放出碳、氮气、水 蒸气和其他气体，形成地球大气层。地球冷却后，地面 就有了水，形成了原始海洋。原始海洋中的有生命特征 的蛋白质和核酸等物质凝聚成独立体系 最后 经历漫长、 复杂的进化，最终形成原始生命。Big Bang

5. After the “Big Bang”, something happened to the earth. Now let’s turn to passage 25 How Life Began On The Earth

6. Read through the text quickly, and answer these two questions. 1. What’s the main idea of the text? 2.What is the topic sentence of each paragraph? Fast reading Fast reading

7. Q1:What’s the main idea of the text? A. how did water begin? B. how did earth begin ? C. how did man begin ? D. how did life begin ?

8. Paragraph 1: Paragraph 2: Paragraph 3: Paragraph 4: Paragraph 5: A widely accepted theoryabout the formation of the universe The formation of the earth The importance of water for life The development of plants and animals on the earth The arrival of humans and their impact on the earth Q2:

9. Careful reading

10. Combine into Explode with fire and rock to produce carbon, nitrogen, water vapour and other gases. dissolve harmful gases Big Bang a cloud of dust a solid globe Atmosphere Water oceans and seas Cool down Read the first three paragraphs and do this exercise in pairs. After be still

11. Come to the last three paragraphs and answer the questions: 1.Which one did begin to appear firstly, animals or plants? 2.Why was it necessary for plants to grow before animals? A. Animals needed plants to protect them from the sun. B. Animals could hide from hunters in forests. C. It was easier for plants to grow. D. Plants provided oxygen for animals to breathe. Plants firstly began to appear on the surface of the water.

12. Small plants in the water Green plants on land Insects on land Mammals on land 1 2 1 2 3 Shellfish and all sorts of fish Amphibian on land and in water forests Reptiles on land Dinosaurs on land life Plants animals 3 4Clever animals on land Read the last three paragraphs again and then complete the blanks.

13. Listen to the last paragraphs and fill in the blanks: Finally about 2.6 ______years ago some small _______animals, now with hands and feet, _________and ______all over the earth. Thus they have, in their_____, become the important animals on the______. But they are not looking after the earth. They are putting too much carbon dioxide into the atmosphere, which ________heat from escaping from the earth into space. As a _____of this, many scientists believe the earth may become too hot to live__. million clever appeared spread return planet prevents result on

14. 10 7 3849615212 11 1. Insects and amphibians appeared. 3. The earth became a solid ball. 5. Reptiles appeared. 7. The earth was a cloud of dust. 9. Shellfish and other fish appeared. 11. Clever animals with hands and feet appeared. 2. Dinosaurs appeared. 4. Small plants grew on the water. 6. Plants began to grow on dry land. 8. Water appeared on the earth. 10. The universe began with a "Big Bang". 12. Mammals appeared. Row order

15. Small plants in the water Green plants on land Insects on land Mammals on land 1 2 1 2 3 Shellfish and all sorts of fish Amphibian on land and in water forests Reptiles on land Dinosaurs on land life Plants animals 3 4Clever animals on land Have a rest.

16. Retell the text, and then write a summary (about 100 words) of the text in your own words.

17. Our universe began in a big bang about 15 billion years ago. The Big Bang is the term used to describe a huge explosion which threw matter in all directions, creating our universe.