1、学习目标：1.知识与技能：学会天文学方面的一些表达，了解地球上生命的起源。2.情感态度与价值观：关注地球，重视保护环。热爱科学、尊重科学。重点难点：讨论和学习地球上生命的起源问题，培养学生的阅读能力。学法指导：讨论、成果展示、略读、跳读。 自主学习1. 重点词汇Astronomy ( ) atmosphere ( ) system( )Violent ( ) solid ( ) explode ( )Carbon ( ) dioxide ( ) oxygen ( ) surface ( ) Planet ( ) harmful ( ) spread ( ) method ( ) 2. Warm
2、ing upQ1: Which astronomers do you know?_. Q2: In our solar system 8 planets circle around the sun. What are they? _. Q3: How much do you know about the universe? What are they?_.3. Fast reading Read the text quickly and write down the main idea for each paragraph.Paragraph 1:_Paragraph 2；_Paragraph
3、 3: _Paragraph 4: _Paragraph5: _我的疑惑：_. 合作探究Detail readingRead the text carefully and answer the following questions 1. Put the order of development of life into time line. (1) ( ) A . Insects and amphibians appeared.(2) ( ) B. Dinosaurs appeared.(3) ( ) C. The earth became a solid ball.(4) ( ) D. S
4、mall plants grew on the water.(5) ( ) E. Reptiles appeared.(6) ( ) F. Plants began to grow on dry land.(7) ( ) G. The earth was a cloud of dust.(8) ( ) H. Water appeared on the earth.(9) ( ) I. Shellfish and other fish appeared.(10) ( ) J. The universe began with a Big Bang.(11) ( ) K. Clever animal
5、s with hands and feet appeared.(12) ( ) L. Mammals appeared.Order:_2. 1. Why was the earth different from the other planets? _2. Why did the plants grow before the animals came? _3. Why is it wrong to show films with dinosaurs and people together? _4. What problem is caused by human beings? _能力提升Sum
6、mary:After the “Big Bang”, the earth was just a cloud of dust. It _ loudly with fire and rock, which were _ _to produce the water vapour, _ and other gases. Then small plants grew. They _and filled the oceans and seas with oxygen. Many millions of years later the first green plants began to _on land
7、. When the plants grew into forests,_ appeared for the first time. They produced young generally by _eggs. When dinosaurs disappeared, _ became more important. Now small clever animals with _appeared and _all over the world .As time _ they covered the earth and they are putting too much carbon dioxi
8、de into the _, which _ heat _ _ from the earth into space. Whether life will continue on earth for millions of years to come will _whether this problem can be solved.随堂小测1. What began to appear on the earths surface when it cooled down?A. water B. gases C. heat D. carbon2. From the Last paragraph we can infer that the author is _.A. confident B. sad C. concerned D. angry3. How many years did dinosaurs exist on the earth?A. More than 140 billion years. B. More than 140 million years C. More than 140 thousand years D. More than 140 years