教学设计
Learning about Language：Important
language points
整体设计
教材分析
The emphasis of this period will be placed on the important new words，expressions and sentence patterns in the parts Warming Up，Pre-reading，Reading and Comprehending.In order to make students understand these important points thoroughly，we can first get students to understand their meanings in the context，then give some explanations about them，and later offer some practices to make students master their usages.Some new words and expressions，such as exist，puzzle，in time，in one's turn，prevent…from and so on are very useful and important.So are the sentence patterns “The earth became so violent that it was not clear whether the shape would last or not.” and “So whether life will continue on the earth for millions of years to come will depend on whether this problem can be solved.” We ought to pay more attention to them and design special exercises.
At the end of the class，the teacher can make students do more exercises for consolidation.In doing so，they can learn，grasp and use these important language points well.
教学重点
1．Enable students to grasp the usages of such important new words and expressions as exist，puzzle，in time，in one's turn，prevent…from，etc.
2．Get students to master the patterns “The earth became so violent that it was not clear whether the shape would last or not.”and “So whether life will continue on the earth for millions of years to come will depend on whether this problem can be solved.”
教学难点
1．Let students learn the usage of the expression “prevent…from…”．
2．Enable students to learn the sentence pattern“It is（not）＋adj.＋that（whether）…”．3．Get students to understand some difficult and long sentences.
三维目标
知识目标
1．Get students to learn and grasp the important useful new words and expressions in this part：astronomy，system，religion，theory，atom，billion，globe，violent，carbon，atmosphere，unlike，fundamental，harmful，acid，chain，multiply，oxygen，exist，thus，dioxide，puzzle，solar system，in time，lay eggs，give birth to，in one's turn，carbon dioxide，preve nt…from 2．Let students learn the following important useful sentence patterns：
1）What_it_was_to_become was uncertain until between 4.5 and 3.8 billion years ago when the dust settled into a solid globe.（be to do；what-clause as the subject）
2）The earth became so violent that it_was_not_clear_whether_the_shape_would_last_or_not.（so…that；it is/was not＋adj.＋whether-clause）
3）What is even more important is that as the earth cooled down，water began to appear on its surface.（what-clause as the subject；that-clause as the predicative）
4）It was not immediately obvious that water was to be fundamental to the development of life.[it is/was（not）＋adj.＋that…]
5）So whether_life_will_continue_on_the_earth_for_millions_of_years_to_come will depend on whether this problem can be solved.（whether-clause as the subject；depend on＋whether-clause as the object）
能力目标
1．Get students to use some useful new words and expressions correctly.
2．Enable students to make sentences with the useful sentence patterns.
情感目标
1．Stimulate students' interest in learning English.
2．Develop students' spirit of cooperation and teamwork.
教学过程
Step 1 Revision
1．Check the homework exercises.
2．Ask some students to talk about how life began on the earth.
Step 2 Reading and finding
Get students to read through Warming Up，Pre-reading，Reading and Comprehending to underline all the new words and useful expressions or collocations in these parts.
Read them aloud and copy them down in the exercise book after class.Try to keep them in mind.
Step 3 Practice for useful words and expressions
1．Turn to Page 28.Go through the exercises in Discovering useful words and expressions with students and make sure they know what to do.
2．Give them several minutes to finish the exercises.They first do them individually，and then discuss and check them with their partners.
3．Check the answers with the whole class and explain the problems they meet where necessary.
Step 4 Studying important language points
1．However，according to a widely accepted theory，the universe began with a “Big
