Unit4 Reading [课件].ppt

Science: The Big Bang（大爆炸） Why is water so important for the beginning of life? 1.Who are the small clever animals with hands and feet? 2. Are they taking care of the earth well? put the order of development  of life into a time line? 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 2. Dinosaurs appeared. 4.Small plants grew on the water. 6. Plants began to grow on dry land. 8. Water appeared on the earth 10. The universe began with a “Big Band”. 12. Mammals appeared. summary After the “big bang”, the earth was still just a cloud of _______,it _______loudly with fire and rock, which were _____ to produce the_________, water vapour and other gases. Then ________ began to appeared on the earth. The cells in the water began to separate. Marine animals came into being. Some animals (amphibian insects) came to land. Reptile appeared. dinosaurs Mammals Man had evolved from apes. They developed new methods of growing food, hunting and moving around. As time went by they covered the earth and have become the most important animals on the planet. water green plants on land 2 3 4 How life began on the earth 5 6 7 8 forests shellfish and all sorts of fish insects (on land) amphibians (on land\ in water) reptiles (on land) dinosaurs (on land) mammals (on land) small clever with hands and feet human small plants in water 1 * * * * * * * * * * Greenhouse effect But they are not taking care of the earth very well. What problem are humans causing ? putting too much carbon dioxide into the atmosphere the earth may become too hot prevents heat from escaping from the earth into space. too hot to live on 8 3 10 9 11 5 1 7 4 12 6 2 Ex.2 on P27 Post-reading Think about what you have read and make choices. 1.Why was the earth different f