必修三Unit4-readingppt课件

Unit 4,Astronomy： the science of the stars,1,Uranus 天王星,Venus 金星,Earth 地球,Mars 火星,Mercury 水星,Neptune 海王星,Saturn 土星,Jupiter 木星,Quiz: In our solar system eight planets circle around the Sun. What are they? Match the names with the planets.,2,Fast reading,Read the passage quickly and find the main idea.,A brief introduction on how the universe developed and how life began on the earth.,3,Careful reading,Para 1:,Para 2: Para 3: Para 4:,Para 5:,A 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 animals on the earth.,The arrival of humans and their impact on the earth.,Read the passage carefully and analyse its structure.,earth, atmosphere and water,life development,human beings,4,1. What is the original earths atmosphere made up of? 2. Why did scientists believe water is fundamental to the development of life? 3. How did water come into being on the earth? 4. Which kind of life-being first appeared on the earth, plants or animals? Why? 5. Why were mammals different from all life forms in the past?,Answer the following questions.,5,Carbon, nitrogen, water vapour, and other gases.,2. Why did scientist believe water is fundamental to the development of life?,Because water allowed the earth to dissolve harmful gases and acids into the oceans and seas to ensure a following chain reaction, which made it possible for life to develop.,What is the original earths atmosphere made up of?,3. How did water come into being on the earth?,The explosion of the earth produced water vapor, which turned into water when the earth cooled down.,6,4. Which kind of life-being first appeared on the earth, plants or animals? Why?,At first, small plants began to appear on the surface of the water, they produce oxygen, which encouraged the later development of early shellfish and all sorts of fish.,5. Why were mammals different from all life forms in the past?,They were different because they produced their young from within their bodies and produce milk to feed them.,7,Let review the evolution of life on the earth.,8,After the “Big Bang”, the earth was full of water.,9,Original cells appeared in the ocean.,10,The cells in the water began to separate. Small plants came into being.,11,Early shellfish and all sorts of fish,12,Some animals (amphibian & insects) came to land.,13,Reptile appeared.,14,dinosaurs,15,mammals,16,Man had evolved from apes.,17,We are making the world better.,We are making the world worse.,Discussion,18,Because they are putting too much carbon dioxide into the atmosphere.,The earth may become too hot to live on .,19,The earth is becoming hotter and hotter!,20,solar energy,plant trees,recycle