必修三第四单元 How Life Began on the Earth 阅读 课件.ppt

reading How Life Began on the Earth 人教新课标必修3 Unit 4 Astronomy: the science of the stars Which came first? The chicken or the egg? Each religion or culture has its own ideas about the beginning of the universe, what do you know about them? Pangu separated the sky from the earth Nuwa mended the heaven and created human beings from the clay(粘土). God created the world and human. Vocabulary solar system n.太阳系 planet n.行星 atmosphere n. 大气层 matter n. 物质 atom n.原子 oxygen n. 氧 carbon n. 碳 nitrogen n. 氮 vapour n. 水蒸气 shellfish n.水生有壳动物 amphibian n.两栖动物 reptile n. 爬行动物 mammal n. 哺乳动物 dinosaur n.恐龙 violent adj.猛烈的；激烈的 harmful adj.有害的 lay eggs 下蛋 give birth to 生产；分娩 prevent…from阻止；制止 Para. 1 The formation (形成) of the earth. Para. 2 The importance of water for life. Para. 3 A widely accepted theory about the formation of the universe. Para. 4 The arrival of humans and their impact on the earth. Para. 5 The development of plants and animals on the earth. Skim for main idea ,and match Detailed Reading Stage 1: Para1-3 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) Was the earth quiet and peaceful after it became a solid globe? No. (3) What did the carbon dioxide, nitrogen, water vapour and gases form? the earth’s atmosphere Why was water so important for the beginning of life? Because water allowed the earth to dissolve harmful gases into oceans and seas. Stage 2: Para4-5 The development of life Water appeared (4) What appeared as the earth cooled down? Water was fundamental for the beginning of life on the earth. Read Para4-5 carefu