人教版高中英语必修三unit4astronomythescienceofthestarswarmingupreading课件

人教版高中英语必修三unit4astronomythescienceofthestarswarmingupreading课件内容摘要：

nto two stages Stage 1 : The development of the earth Stage 2 : The development of life (para 1— 3) (para 4— 5) Stage 1: The development of the earth (1) After the Big Bang, what was the earth like? a cloud of dust a solid globe exploded with fire and rock produced water vapour and gases (2) What happened next? (3) What did the water vapour and gases form? the earth’s atmosphere Water appeared (4) What appeared as the earth cooled down? water is important for the beginning of life on the earth. Why is water so important for the beginning of life? Because water allowed the earth to dissolve harmful gases into oceans and seas. Stage2 The development of life small plants appears in water life developed after water appeared? Shellfish and all sorts of fish life developed in water next? green plants began to grow on land insects appeared about the life on land? amphibians on land and in the water forests 4. What life developed next on land? reptiles appeared dinosaur developed life developed after forests appeared? mammals on land life developed after dinosaurs?。