unit13.docx

1、unit13Unit 13 The water planet.Brief Statements Based on the UnitAs we all know, the earth is an ocean planet and 99% percent of the living space on earth is in the oceans. It is water that makes the ocean such a great place to live in. This unit mainly deals with the properties of water and how the

2、 properties of water make the ocean become so important. We learn this unit to help students not only know about the properties of water, but also learn how to use water in a good way. Besides, we learn this unit to let students realize the importance of protecting water. Of course, it is necessary

3、for students to master the important phrases and sentences in the unit. Meanwhile we should review some important usage of Modal Verbs. Teaching Goals1. Talk about water and the ocean.2. Practise communicative skills.3. Review Modal Verbs.4. Write an explanation paragraph.Background Information1. Wh

4、at Lies under the Blue Water?Just like the houses we live in, the ocean has several “floors” or layers. Different fish live on different layers and are neighbours, though not always friendly ones!The oceans top layer is the sunlit zone(透光层).It goes down to around 200 meters below water. This layer i

5、s warm and bright. It is also home to most plants and fish. Many fish in this layer are streamlined, so they can quickly swim from danger and catch food.The twilight zone(弱光层) is the next layer and is from about 200 to 600 meters below water. Almost no plants grow here.Many animals in this zone swim

6、 up to the surface at night to feed, and move into deeper waters during the day. They also eat each other, so many of them have sharp teeth and very big mouths.Many fish in this zone dont have a streamlined body because they lie and wait for prey to come to them.Below the twilight layer is the midni

7、ght zone(无光层).It is from 600 meters to the bottom of the sea.The water is cold and completely dark. No plants live here but many small animals can.Many animals in the twilight and midnight zones produce their own lights.The angler-fish(琵琶鱼) is one of them. It has a beautiful light on its head to att

8、ract prey!Maybe you have seen one of the coolest films Finding Nemo (海底总动员).Do you remember Marlin, Nemos father, “borrowed” light to help Dory read?That wasnt a flashlight, it was a fish! They also use light to frighten enemies and to “talk” with each other.2. WaterA family of six needs over 20 gal

9、lons of water a day, just for basic drinking, cooking and keeping clean; but only one in three of the worlds households has a water supply in the home.Most others get their water from rivers, lakes springs or holes in the ground, or, in town, from stand-pipes shared with hundreds of other families.T

10、hroughout the worlds poorest countries women damage their health and lose hours of every day carrying huge containers of waterup to 44 lbs in weightoften from sources several miles away.All too frequently they bring home sickness or death, as well as water. Untreated water, which may have come from

11、a muddy hole shared with cattle, can be lethal, especially for young children. To sink a well or pipe water from a natural spring, and maintain the system afterwards, people need access to land with a water source, to capital, equipment and technical know-how. In towns they may need to lobby the loc

12、al water authority to repair or extend existing systems.Water is precious, and access to it gives powerto landowners with wells on their land, or to country controlling major international rivers. The demands on the earths water resources are growing rapidly, partly as a result of population growth,

13、 but even more because industry now uses such huge quantitiesit takes 100 000 gallons to produce a car.Teaching Time: Five periodsThe First PeriodTeaching Aims:1.Learn and master the new words and the useful expressions of this part.Words: cube, sailor, disadvantages, entertainmentPhrases: come up w

14、ith, happen toUseful expressions: The water is being used to/forWe should/couldIf wewe canIt would be better2. Learn something about water by doing experiment.3. Do some listening.4. Improve the students speaking ability by talking.Teaching Important Points:1. Make the students be free to talk about

15、 water.2. Improve the students listening ability by listening.Teaching Difficult Points:1. How to finish the task of speaking.2. How to improve the students listening ability.Teaching Methods:1. Listening-and-answering activity to help the students go through with the listening material.2. Individua

16、l, pair or group work to make every student work in class.Teaching Aids:1. the multimedia2. the blackboard3. an empty glass, a bottle of water and a bottle of vegetable oilTeaching Procedures:Step Greetings and Lead-inT: Hello, everyone.Ss: Hello, teacher.T: Attention, please. As we all know, every

17、year during the Spring Festival and Lantern Festival in our country, people like to see the lion dance and guess the riddles. Do you like to guess the riddle, then?Ss: Yes.T: OK. Now I have a riddle. Please guess it.(Teacher uses the multimedia to show the riddle on the screen.)Its very important to

18、 all the animals and plants.Its also important to human beings.Its liquid at room temperature.Every day you keep in touch with it.You cant live without it.(a thing)T: Whats it?Ss: Its very easy. Its water.T: Yeah, today we will talk about water. Now please tell me what you know about water.S1: Water

19、 is used to drink.S2: Water can be used to water the flowers.S3: I think water can be used to make electricity.Step Warming upT: Thank you for your ideas. Next we will make some interesting experiments. Maybe you can learn more about water from the following experiments. S4, would you like to come h

20、ere to help me?S4: Id love to.T: Now, look at Li Lei and me. We will begin. You should watch the experiment carefully and try to tell me what happens and why.(Teacher puts a bottle of water, a bottle of vegetable oil and an empty glass on the desk.)T: S4, pour some water and some vegetable oil into

21、the empty glass. Other students, please watch carefully.( A few seconds later.)Ss: Fantastic! The liquid in the glass has become two parts.T: Try to describe it in detail.S5: Let me try. The part above is vegetable oil and the part below is water. But I dont know why.T: Good question. Whod like to a

22、nswer his question? (Nobody answers his question.)T: Perhaps it is a little difficult to answer it immediately. Now you can have a discussion about the reason for it, using what you have learnt in physics.(Teacher lets students discuss in groups of four. A few minutes later, teacher checks their ans

23、wers.)T: Who wants to explain the phenomenon?S6: I think water is heavier than oil, so vegetable oil is on the top of the water.T: Who has different ideas?S7: I think we should say that the density of water is higher than the density of vegetable oil, so the result formed.S8: Whats the meaning of “d

24、ensity”?S9:“Density” is “密度” in Chinese.T: Do you agree with the reason for it?Ss: Yes. We agree with the idea.T: As we know, if we pour milk and water into one glass, we cant tell where water is and where milk is. But just now we poured oil and water into one glass, it is so different now. Do you k

25、now why?Ss: Because oil cant dissolve in water, but milk can.T: Very good. Lets make a summary about the experiment. If we pour vegetable oil and water into one glass, the liquid will become two parts because oil cant dissolve in water. Since the density of water is higher than vegetable oil, vegeta

26、ble oil will be on top of the water. Is that clear?Ss: Yes.T: Would you like to watch another experiment?Ss: Id love to.T: OK. Ill perform the next experiment by myself. Look at me. I have a glass of water. Now Ill cover it with a piece of thick paper. Attention, please.(Teacher puts one hand on the

27、 paper and turns the glass upside down. Then teacher slowly takes his/her hand away from the paper.)T: What can you see?Ss: The piece of paper doesnt fall and the water in the glass doesnt flow.T: Yes. You are right. Now you are given a few minutes to have a discussion about the reason for it.(Teach

28、er gives students a few minutes to discuss, and then checks their answers.)T: Who can tell us the reason why the piece of paper doesnt fall and the water doesnt flow?S10: I want to have a try. When the glass of water covered with a piece of paper is turned upside down, the pressure from air to the p

29、iece of paper is bigger than the pressure from the water in the glass to the piece of paper. So the paper wont fall and the water wont flow.T: Excellent! Thank you for your explanation. I am very glad to see that you are all interested in making experiments. After class, you can carry out another tw

30、o experiments on Page 17.When you perform them, try to describe what happens and why. OK?Ss: OK.T: Now, lets look at a picture.(Teacher shows a picture on the screen.)T: What can you see?Ss: There is a river in the picture, but its very dirty.T: Anything else?S11: There are some plastic bags and emp

31、ty tins on the surface of the river.T: Yes. We all know water is important to human beings and all the animals and plants. Unfortunately water is being polluted now. What do you think we can do to protect the water on our planet?(Teacher gives students enough time to prepare. When they prepare, teac

32、her goes among the students to help them to express their ideas correctly.)Sample answer:To protect the water on our planet, I think we should save every drop of water and stop throwing rubbish into water. Besides, we should try our best to help the people around us realize the importance of using and protecting our water.Step ListeningT: Next, lets do some listening. Turn to Page 18 and loo