how life began on the earth 公开课

1、整理ppt1Unit 4 Astronomy: the science of the stars整理ppt2We live on the same planet the earth整理ppt31. Do you know the origin of life on earth?2. Each religion or culture has its own ideas about how life began on earth.整理ppt4 In Chinese culture_ separates(分分) the sky from the earth.Pangu 盘古盘古skyearth整理p

2、pt5_ made human beings.Nuwa (女娲女娲)整理ppt6In western countries:_ created the world and all living things.God (上帝上帝)整理ppt7Do you know what a scientific idea is?Background knowledgeThe Big Bang is the term used to describe a huge explosion that scientists believe happened about 15 billions years ago. No

3、body knows what caused the Big Bang. But it was the event that created our universe. The Big BangThe universe began with a Big Bang.整理ppt8 Read the passage on P25 quickly, and match the right main idea of each paragraph. How many parts can the text be divided into?Step 1. Fast readingHow life began

4、on the earth整理ppt9Para.1 Para.2Para.3Para.4Para.5 A theory about how the universe was formedThe formation(形成）形成） of the earthThe importance of water for lifeThe development of plants and animalsThe arrival of humans and their effects on the earthPart1: The development of the earthPart2:The developme

5、nt of life.整理ppt10( 2 ) Detailed ReadingPart 1(13): The development of the earth整理ppt11Part1 (para13) The development of the earth(1) After the Big Bang, what happened?(2) What happened to the solid globe next?(3) What did the water vapour and gases were to make?(4) What appeared after the earth coo

6、led down?(5) What did the water do?How did the earth come into being?整理ppt12(1) After the Big Bang, what happened? a cloud of dust a violent solid ball Settled into整理ppt13exploded with fire and rock produced water vapour and gases(2) What happened to the solid globe next?In time整理ppt14(3) What did t

7、he water vapour and gases were to make?the earths atmosphere整理ppt15Water appeared on its surface which is important for the beginning of life on the earth. (4) What appeared after the earth cooled down?整理ppt16(5) What did the water do?It allowed the earth to dissolve harmful gases and acids into the

8、 oceans and seas.整理ppt17a cloud of _ Big Banga solid _slowly combinethe earth _ downit exploded loudly with _ and _waterthe earths _dustball/globefire rockatmospherecooledHow did the earth come into being(产生）产生）?整理ppt18 According to the pictures, have a try to retell the development of life.整理ppt19A

9、 cloud of energetic dust A solid ballAtmosphere A world full of water4132Combine into Explode with fire and rockdissolve harmful gases Cool down 整理ppt20Part 2 (Part 2 (45) The development of life The development of life整理ppt21Part2 (para45) The development of lifeRead para4 carefully and make a time

10、line of the development of life整理ppt22water 1. 2. 10. 3. 4. insects (on land)5. 6. 7._8. dinosaurs (on land)9._ 11. small _ in water_ and all sorts of fishgreen plants on land _(on land and in water)forests (on land) (on land)small clever animals with _plantsshellfishamphibiansreptilesmammalshands a

11、nd feet1. a timeline of the development of life整理ppt23整理ppt24整理ppt25the cleverest animals整理ppt26 The arrival of _ encouraged the _of early _. Many millions of years later _ began to appear _. Later _ appeared. Some were_. Others called _, were able to live on lands well as _. When the plants grew in

12、to forests, _appeared for the first time. After they disappeared, _became more important. They were the last group of animals different from because they _milk from within their bodies.development shellfish and all sorts of fish on land land animalsamphibians dinosaurs mammals produced small plants

13、the first green plants insects in the sea整理ppt27Read pare5 carefully .find out the answer.1. What problem is caused by human being?They caused global warming.They caused global warming.整理ppt28整理ppt29The earth is getting warmer each year.what effects will this have? How to solve this problem?整理ppt30Suggested Answers: The earth will be so hot that no life will exist（存在）（存在）on the earth any more. To solve this problem, people should protect the earth carefully. They must stop putting too much carbon dioxide into the air , reduce pollution,