北师大版高二选修8教案： Unit 22 Period 3新.doc

the third period lesson 1 global warming 续teaching goals 教学目标1. target language目标语言a. 重点词汇和短语consensus, beyond, relevant, refer, bounce, pin, coincidence, condemn, federal, reservation, sacrifice, advocate, recycle, substitute, beyond ones control, take action, ahead ofb. 重点句子in the last few decades, scientists have reached consensus and reported that human beings are causing changes in the earths climate something previously seen as beyond our control.2. ability goals 能力目标 learn what global warming is and enable students to learn its causes and consequences.3. learning ability goals学能目标by reading an article help students to learn how they can help solve the problem of global warming.teaching important points教学重点what human activities are causing global warming and how we can help solve the problem of global warming.teaching difficult points教学难点how we can help solve the problem of global warming.teaching methods教学方法 listening, reading, discussing.teaching aid 教具准备multimedia computer.teaching procedures & ways 过程与方式step vi analyzing the texthelp students analyze the structure of the text. ask students to discuss in groups and later each group will speak out their opinions. after this, show the suggested answers on the powerpoint.t: ok. lets read the text again. please look at the structure of the text. you are given 5 minutes.t: please stop here. im glad you thought actively and had a heated discussion. what is its writing style? ss: this text is an expository writing.t: what is the topic of the text? what is the text about?s1: global warming.s2: the text introduces what global warming is.s3: its causes and consequences.s4: and how we can help solve the problem of global warming. t: quite good. how many parts consist of the article? whats the main idea of each part?s4: in my opinion the article is made up of four parts. in the first paragraph the author raises the question. in the second paragraph we can find its definition. and the third and fourth paragraphs tell us its causes and consequences. and the last part the author gives us some tips on how to solve the problem.t: well done!if students have different opinions, teacher may help them analyze the text.show the following on the powerpoint.part1 (the first paragraph) global warming could be one of the biggest environmental problems facing the 21st century.part2 (para.2) what global warming is.part3 (para.3-4) its causes and consequences.part4 (para.5) tips on how to solve the problem.t: after learning the tips on how to solve the problem, lets discuss what we will do every day to help reduce greenhouse gases. please make your voice heard and get involved in the discussion. after the discussion, please write your suggestions on a piece of paper and put it on your bulletin board so that you can share your ideas with the whole class.step vii discussiondivide the students into different groups and discuss the questions of ex 4 on page 7. they are given several minutes to discuss. each member is encouraged to think actively and participate in the discussion. make sure all the students have their own opinions. every group should have their secretary to write down the discussion. then each group should pin the suggestions on the bulletin board so that everyone can read them and learn about others good way to reduce green house gases. t: please work in groups and express yourself freely. because everyone has his or her own practical way, please share your ideas with your group members.t: before starting your discussion, please read the following.show the following on the powerpoint.the top five global warming polluters!1. the united states2. china3. russia4. japan5. americas cars and light truckschina to invest $175 billion in environmental protection over five yearschina has created an “economic miracle” over the past two decades, air pollution is choking its cities, chemical spills are fouling its rivers and drinking water supplies, soil contamination is undermining its agriculture, and raw sewage is causing widespread disease. this environmental toll has led to internal riots, international protests, and the arrest and trial of a leading chinese environmentalist. in 2006, china pledged to invest $175 billion by 2010 to control water pollution, improve air quality, increase solid waste disposal and reduce soil erosion investments intended to pay economic as well as environmental dividends.a sample of ex 4 on page 7responsible choicesthe choices we make and the products we buy test our commitment to maintain a healthy planet. when we burn fossil fuels such as oil, coal, and natural gas to run our cars and light our homes, we pump carbon dioxide (co2) into the air. this thickens the heat-trapping blanket that surrounds the planet, causing global warming. choosing modern technology can reduce our use of fossil fuels and help protect the planet. these steps will help curb global warming, save you money, and create a safer environment for the future. drive smart!a well-tuned car with properly inflated tires burns less gasoline cutting pollution and saving you money at the pump. if you have two cars, drive the one with better gas mileage whenever possible. better yet, skip the drive and take public transit, walk, or bicycle when you can.replace incandescent light bulbs with compact fluorescents bulbs.especially those burn the longest each day. compact fluorescents produce the same amount of light as normal bulbs, but use about a quarter of the electricity and last ten times as long. each switch you make helps clean the air today, curb global warming, and save you money on your electricity bill.become a smart water consumer.install low-flow showerheads and faucets and youll use half the water without decreasing performance. then turn your hot water heater down to 120f and see hot-water costs go down by as much as 50 percent.buy energy-efficient electronics and appliances.replacing an old refrigerator or an air conditioner with an energy-efficient model will save you money on your electricity bill and cut global warming pollution. look for the energy star label on new appliances.plant a tree, protect a forest.protecting forests is a big step on the road to curbing global warming. trees breathe in carbon dioxide, but slash-and-burn farming practices, intensive livestock production, and logging have destroyed 90 percent of the native forests in the united states. and you can take action in your own backyard planting shade trees around your house will absorb co2, and slash your summer air-conditioning bills. reduce! reuse! recycle! producing new p