浙江省杭州市塘栖中学高中英语必修三：unit4HOWLIFEBEGANONTHEEARTH教学课件.ppt

Welcome;HOW LIFE BEGAN ON THE EARTH?; Read after the tape and do the match work. ;Para1 How did the universe begin according to a widely accepted theory ?;The universe began with the Big Bang. ; Para1: The Big Bang threw ______in all directions Atoms Stars and other bodies;Para 2;para 2;exploded with fire and rock;(3) What did the water vapour and gases form?; Water appeared;Para3 1. Why was the earth different from the other planets?;Para3 1. Why was the earth different from the other planets?; 2. Why was water so important for the beginning of life? ;Para4 The development of life;early ____and all sorts of fish;early _______ and all sorts of fish; small plants appeared in water;Shellfish and all sorts of fish;green plants began to grow on land;amphibians on land and in the water; reptiles appeared;mammals on land; small clever animals;Para5 What problem are these clever animals causing?;What will happen when we put too much CO2 into the atmosphere?; greenhouse effect;homework;;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