定稿book4unit2usinglanguagereading.ppt

Book4 Unit 2 Using Language,Lead in,In this unit we have learnt about a great man, do you still remember who he is? What is his achievement? Can you think of other ways to increase our crop harvest?,What is the matter we put on the soil which makes crops grow ? It is fertilizer.,chemical fertilizers natural fertilizers,Now, which one do you prefer?,A,B,Why?,Its a product of organic farming.,A,Its a product of chemical farming.,B,Chemical or Organic Farming?,Scanning,1. What is organic farming? Farming without using chemicals. 2. What is the goal of using organic farming methods? To grow good food and avoid damaging the environment or peoples health.,Part 1 (Para.1-2) Chemical farming part 2 (Para. 3-4) Organic Farming,Divide the text into two parts.,？,？,Task1: skim and match the main idea of each paragraph.,B. Long-term use of chemical fertilizers can harm the land and peoples health.,D. Farmers and customers turn to organic farming.,C. Organic farming methods to keep the soil fertile.,A. Problems caused by chemical fertilizers.,P1.,P2.,P3.,P4.,Task2: Para 1. Read and answer.,What advantages does chemical farming have? Chemical farming can stop crop disease and increase production.,Task4: Para. 2 Read and fill the form.,bacteria and pests,nutrition,land,Peoples health,cancer other illnesses,Task5: Para. 3 True or False,Organic farming means farming without using any chemicals. Organic farmers prefer using fertilizers to make the soil richer in minerals. Farmers want to keep their soil fertile and free of disease. Organic farming would pollute the environment.,natural waste from animals,not pollute the,T,T,F,F,To make the soil richer in minerals and therefore makes it more fertile.,Using natural waste from animals as fertilizer.,a organic farming method,A healthy soil can reduce disease and helps crops grow strong and healthy,What is the purpose?,Para. 4 find out the topic sentence,Can you find out 3 more methods of organic farming to keep the soil more fertile?,1:Changing the kind of crop in each field every few years.,2:Using different levels of soil,3:Planting grass between crops and leave it in the ground,Changing the kind of crop in each field every few years.,Using different levels of soil,1. To use different levels of soil.,3. To renew the minerals in the soil and help it become rich.,Planting grass between crops and leave it in the ground,2.To prevent wind or water from carrying away soil and act as a natural fertilizer.,Methods Purposes,Para. 4 Match each method with its purpose.,After reading, please tell me:,1. Is it chemical or organic farming? 2. How do you know?,Situation 1: The farmer is using fertilizers to keep the vegetable free from pest.,Chemical farming,Situation 2: Lao Wang grows soybeans in his field last year and grows corns this year.,organic farming,Grow different crops every year.,Situation 3: Lao Li throw the nitrogen fertilizer(氮肥) in his field to make his soil rich in minerals.,Chemical farming,Use chemicals,Situation 4: Li Hua only use natural fertilizers to grow his cabbage. Thats why his cabbage is damaged by pests.,Organic farming,Which kind of farming do you support?,Organic farming ？,Chemical farming ？,Competition,Lets find the advantages of Organic farming.,Eg: Organic farming is good for peoples health. Organic farming can ,Who can find more?,The advantages of Organic farming,Environmentally friendly Make the soil fertile Make full use of soil Do no harm to peoples health. Cost little money Can be used for a long time ,A stubborn farmers idea: Chemical Farming is better.,Help crops grow fast Kill pest Increase production Stop crop disease Easy to use Become effective in a short time ,Find disadvantages of chemical farming to persuade the farmer.,Chemical farming can help crops grow fast, but the crops may grow too fast to be full of nutrition.,Homework:,Write a composition about the advantages of organic farming and the disadvantages of chemical farming t