浙江省杭州市塘栖中学高中英语必修三教：Howlifebeganontheearth(final)教学课件.ppt

solar system;Water had also appeared on other planets like Mars but, unlike the earth, it had disappeared later. ;No one knows exactly how the earth began,;⑤They were in time to produce carbon,nitrogen, water vapour and other gases, which were to make the earth’s atmosphere. ;a cloud of dust;Before life appeared;Many millions of years later, the first extremely small plants began to appear on the surface of the water. ; After that, some huge animals, called dinosaurs, developed. They laid eggs too and existed on the earth for more than 140 million years. ;Shellfish fish; Finally about 2.6 million years ago some small clever animals, now with hands and feet,appeared and spread all over the earth.Thus they have, in their turn, become the most important animals on the planet. ;They developed new methods of growing food, hunting and moving around. ;The development of life;（ ）A Insects and amphibians appeared. （ ）B Dinosaurs appeared. （ ）C The earth became a solid ball. （ ）D Small plants grew on the water. （ ）E Reptiles appeared. （ ）F Plants began to grow on dry land. （ ）G The earth was a cloud of dust. （ ）H Water appeared on the earth. （ ）I Shellfish and other fish appeared. （ ）J The universe began with a “Big Bang”. （ ）K Clever animals with hands and feet appeared. （ ）L Mammals apeared.;Retelling