2. Do you know the position of the earth?

3. The Solar system 水星 金星 火星 木星 土星 天王星 海王星

4. How Life Began On The Earth

5. Warming up There are many different ideas about the origin of the life on the earth,and do you know any of them?

6. 盘古开天

8. The Big Bang Theory is the dominant（占 优势的）scientific theory about the origin of the universe. According to the Big Bang, the universe was created sometime between 10 billion and 20 billion years ago from a cosmic (宇宙的) explosion (爆炸)in all directions. Although the Big Bang Theory is widely accepted, it hasn ’ t been proved and left a number of unanswered questions.

9. The Big Bang Theory

10. Do you know how the earth began and how life began on the earth?

11. First reading:read quickly and find out the main idea of each part. _____life in water _____the beginning of life _____the development and the problems _____life on land P2 P1 P4 P3

12. Further-reading: Para 1 1.What is the earth’s atmosphere made of? 2. Do the exercise1—1 and 2 on P26. It includes water vapor, carbon dioxide, oxygen, nitrogen and other gases. Keys: BB

13. Para 2: Go through this part quickly and finish the exercise 3 on P26. Key: B

14. Para 3: Go through this part quickly and answer the questions: 1.According to the scientists, what helped life to develop? 2.Why is it wrong in films to show dinosaurs and people together? Taking carbon dioxide from the atmosphere and filling the air with oxygen helped life to develop. Human beings appeared only after the dinosaurs had disappeared.

15. Read through the text to find out the correct time order in the Exe2 on P27. Keys: D B I G E H A C F J

16. Para 4 : Answer the question: 1.Why are the humans the cleverest animals on the earth? 2.Choose the correct answer to Exe4 on P27. Because they have hands and feet and develop the methods of growing food, hunting and moving around. Key: B

17. Have a try: Sum up the text: The beginning of the earth just a cloud of ______ Then it combined into a_ ___ Exploded with ___________ They produced__________. Oxygen, nitrogen… They are the earth’s__________. Very________ dust ball fire and rock water vapor atmosphere hot

18. cool down ________ appeared on its surface. It makes the earth show its special qualities. The earth dissolves ___________ _____. So life began to develop. Early______________________________ appeared because of small________growing in the water on its surface. Water harmful gases. shellfish and all sorts of fish plants

19. millions of years later Green plants appeared____________. Taking…and filling… helped life to develop. ____________appeared. Plants grew into forests; _______appeared. Reptiles_________to produce young. Dinosaurs appeared. They disappeared; ________ became more important. They are the ____group of the animals. on the land Land animals reptiles laid eggs mammals last

20. Later Small animals with________________appeared. They developed new methods of __________________. They became the most important animals. The earth has changed a lot because ____________________________________. Conclusion: hands and feet growing food, hunting and moving around they are not taking care of the earth very well The earth has a history of development. Plants and animals on the earth are always changing it. So we human beings must take care of the earth well.

21. Homework 1.Read the text again and again and find out the difficult points. 2.Review the new words of this part. 3.Do the exercises of Learning about language on page 27.