how-life-began-on-the-earth-公开课.pptx

Unit 4 Astronomy:the science of the starsWe live on the same planet the earth1.Do you know the origin of life on earth?2.Each religion or culture has its own ideas about how life began on earth.In Chinese culture_ separates(分分)the sky from the earth.Pangu 盘古盘古skyearth_ made human beings.Nuwa(女娲女娲)In western countries:_ created the world and all living things.God(上帝上帝)Do 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.Nobody knows what caused the Big Bang.But it was the event that created our universe.The Big BangPre-readingThe universe began with a Big Bang.While-reading 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 on the earthPara.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 development of life.(2)Detailed ReadingPart 1(13):The development of the earthPart1(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 cooled down?(5)What did the water do?How did the earth come into being?(1)After the Big Bang,what happened?a cloud of dust a violent solid ball Settled intoexploded with fire and rock produced water vapour and gases(2)What happened to the solid globe next?In time(3)What did the water vapour and gases were to make?the earths atmosphereWater appeared on its surface which is important for the beginning of life on the earth.(4)What appeared after the earth cooled down?(5)What did the water do?It allowed the earth to dissolve harmful gases and acids into the oceans and seas.a 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）?According to the pictures,have a try to retell the development of life.A cloud of energetic dust A solid ballAtmosphere A world full of water4132Combine into Explode with fire and rockdissolve harmful gases Cool down Part 2(45)The development of lifePart2(para45)The development of lifeRead para4 carefully and make a timeline of the development of lifewater 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 and feet1.a timeline of the development of lifethe cleverest animals 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 into 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 the first green plants insects in the seaRead pare5 carefully.find out the answer.1.What problem is caused by human being?They caused global They caused global warming.warming.The earth is getting warmer each year.what effects will this have?How to solve this problem?Suggested 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,control the population and so on.We only have one earth.Without other livings,we human cannot live.Homework1.Read the passage more after class.2.Write a composition about how to stop global warming.