Unit4 Globalwarming
perhaps/maybe they should/ought to... why don't you do something about it？
语法
“it”的用法(the use of “it”)(2)
...it_is human activity that has caused this global warming...
教
学
重
点
1.get students to know about global warming and its effect；to realize what we can do about global warming.
2.have students learn some useful new words and expressions about global warming and let them learn effective ways to master them.
3.enable students to grasp and use the expressions of agreement and disagreement，blame and complaint.
4.let students learn the new grammar item：the use of “it”(2).
5.develop students' listening，speaking，reading and writing ability.
教学难点
1.enable students to master the use of “it”(2).
2.let students learn to write a short passage to tell others how to solve the problem of global warming.
3.develop students' integrative skills.
课时安排
periods needed：6
period 1 warming up，pre－reading，reading and comprehending
period 2 language study
period 3 grammar—the use of “it”(2)
period 4 listening and speaking
period 5 reading and writing
period 6 summing up，learning tip and assessment
period 1 warming up，pre－reading，
reading and comprehending
整体设计教学内容分析 this is the first teaching period of this unit.the central part of this period is the reading passage with the title of “the earth is becoming warmer—but does it matter？” talking about the global issue which has a great effect on human beings' life.warming up gives six pictures to help students list the sources of energy they can think of in our daily life.then they will be led to discuss which energy source is “renewable” and which is “non－renewable”.this part is designed to help the students to recall their background knowledge about energy and prepares students for the whole unit.pre－reading provides a picture of a greenhouse and then tells us what a greenhouse is and what “greenhouse gases” are.the students will be led to discuss what they think greenhouse gases do，leading to the topic of the reading passage.reading is a passage from an environmental magazine for young people.it puts forward the possible effect of increased carbon dioxide in the atmosphere and different points of view about it.it also analyzes the causes of the earth's increased temperature.it poses questions and encourages students to think about the issues.there are two graphs in it that tell us the “temperature difference from long－term average,1860－” and “carbon dioxide content in the atmosphere,1957－1997”.characters in the passage—dr janice foster，george hambley and charles keeling are all real persons and their views reflect the views of some scientists today.
