【名校课件】人教版必修3：Unit4Astronomy-Warming-upreading（浙江平桥二中）.ppt

Unit 4 Astronomy: the science of the stars;Warming up;海王星 Neptune ;Reading HOW LIFE BEGAN ON THE EARTH;;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.;;10;Read the text carefully and think about what you have read and discuss these questions in pairs. ;1. Why was the earth different from the other planets? Because water remained on the earth. 2. Why did the plants grow before the animals came? Because plants provided oxygen for animals to breathe. 3. Why is it wrong to show films with dinosaurs and people together? Because dinosaurs died out long before human beings developed on the earth. ;4. There used to be nine planets in the solar system. Recently scientists have decided that one of them can no longer be considered a planet. Do you know the name of that planet? Do you know why they removed it? The name is Pluto. Scientists now think it is too small to be called a planet. 5. What problem is caused by human beings? Human beings cause global warming.;Read the text and fill in the blanks in the following form.;Between 4.5 and 3.8 billion years ago;Many millions of years later;Many millions of years later;About 2.6 million years ago;How life began on the earth;a solid _____;early _________ and all sorts of fish;How life began on earth is one of the biggest puzzles that scientists found hard to solve. What other puzzles are hidden in the passage? Find them out and do some research.