英语：Unit4Astronomy-warmingupreading教案（新人教版必修3）.doc

第  PAGE 3 页 共  NUMPAGES 3 页 Unit4 Astronomy: the science of star-Warming up Reading教案 How life began on the earth Step one: warming up Task 1: Commom sense(常识) of science. Physics, chemistry, biology（study of life),geology(地质学) and mathematics are science subjects. Some science subjects will study two or more of these subjects, for example,the study of physics and mathematics is astronomy(天文学). Can you understand the following combined science subjects. physics +mathematics= astronomy geology+physics = geophysics（地球物理学） biology+chemistry=biochemistry( ) /medicine( ) geopolitics （地缘政治学）=_________+_________ bioengineering(_____________)=_____________+_______________ task 2: Common sense of biology study of the groups of life (生命的种类/物种) Look at the pictures on the screen and judge the groups as quickly as you can. What is the most important condition for life to develop(grow)?(water, airoxygen) Step two: Pre-reading The world is like a big family. It’s wonderful and colorful because of different kinds of life living together.But how did life begin on the earth? The first question for scientists to answer is how water appeared on the earth? Step three: Reading Task1: Fast-reading(Para1) What is the important event(事件) to the earth before the appearance of water? Why is water important for the beginning of life? Task2: Sacnning (Para1,2,3) the beginning of water the beginning of life Scan Para1: the beginning of water 1.the Big Bang 2.a cloud of dust (combine into) 3.a ball/a solid shape (explode) 4.water vapour, oxygen,…and other gas (cool down) 5.water Scan Para2,3: the beginning of life (put them into right order) A. insects and amphibians appear B.reptiles appear C.shellfish and other fish appear D.dinosaurs appear E.small plants grow on the water F.plants begin to grow on dry land G.mammals(including