（公开课课件）必修三Unit-4-How-life-began-on-the-earth.ppt

1、Reading:How life began on the earthGoal:Methods:Reading and discussingScanning Scan the passage and find out the answer to the question:When did human beings appear?Scanning Q:When did human beings appear?A:About 2.6 million years ago.About 2.6 million years ago,human beings appeared.4.6 billion yea

2、rs agoSkimming Read the passage carefully and find out the main idea for each paragraph.Para.1Para.2 Para.3Para.4 Para.5The universebegan with a_.“Big Bang”.Para 1SkimmingPara.1Para.2 Para.3Para.4 Para.5A widely accepted theory about the formation of the universe.Para 1Skimming Read Para 2 and try t

3、o answer the following question:After the Big Bang,what happened?Para 2a cloud of dust a solid ballatmosphere 54settled into cooled down 填动词Para 2_fire and rockexploded with _ water vapor and gases123_produced_water _appearedSkimmingPara.1Para.2 Para.3Para.4 Para.5A widely accepted theory about the

4、formation of the universe.The formation of the earth.Para 2What did the water do?It allowed the earth to dissolve harmful gases and acids into the oceans and seas.Para 3SkimmingPara.1Para.2 Para.3Para.4 Para.5A widely accepted theory about the formation of the universe.The formation of the earth.The

5、 importance of water for life.Para 31.2.3.4._(on land)5.6.7._8._(on land)9._ small _ in water_ and all sorts of fishgreen plants on land _(on land and in water)forests (on land)(on land)plantsshellfishamphibiansreptilesmammalsPara 4insectsdinosaursSkimmingPara.1Para.2 Para.3Para.4 Para.5A widely acc

6、epted theory about 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.Para 4Human beings appeared and spread.Para 5 They are putting too much _ into the atmosphere,which prevents heat from escaping from the ear

7、th into space.carbon dioxideWhat main problem is caused by human beings?Para 5They cause global warming.SkimmingPara.1Para.2 Para.3Para.4 Para.5A widely accepted theory about the formation of the universe.The formation of the earth.The importance of water for life.The development of plants and anima

8、ls on the earth.The arrival of humans and their impact on the earth.Para 51073849615212 111.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.Dinosau

9、rs 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.Put the order of the development into a timeline.Discussion waterWhat can we do to protect the earth?forests animals plants atmosphere water Write an article on what we can do to protect the earth according to the discussion(At least 3 aspects,about 150 words).