Book-4-Unit2-chemica-or-organic-farming.ppt

1、conventional food,organic food,organic food,What is the substance we put on the soil which makes crops grow?,fertilizers,There are two kinds. They are chemical fertilizers and natural ones.,How many kinds of fertilizers do farmers use?,Which kind of fertilizers do farmers use when they are doing org

2、anic farming ?,natural waste from animals,Which kind of fertilizers do farmers use when they do chemical farming ?,chemical fertilizers,Chemical or organic farming?,Para1: para2:,A new discovery of scientists.,Several problems caused by using chemical fertilizers.,para3: para4:,The advantages of usi

3、ng organic farming.,Some methods to keep the soil fertile.,Structure of the text,Reading,Using chemical fertilizers for a long time can hurt the land and also peoples health.,1.Why are chemical fertilizers so popular in farming today? 2.Do you think it is really a great way?,They are a great way to

4、stop crop disease and increase production.,No.,Para1:,A new discovery,What problems can be caused by using chemical fertilizers? (disadvantage),Firstly, they damage the land by killing the helpful bacteria and pests.,Chemicals also stay in the ground and underground water for a long time,which affec

5、ts crops and, therefore, animals and humans. And many of the chemicals can lead to cancer or other illnesses.,In addition, fruit, vegetables and other food grown with chemical fertilizers usually grow too fast to be full of much nutrition.,Para2: several Problems caused by using chemical fertilizers

6、,What is the advantage of using natural fertilizer?,Para3:The advantages of using organic farming.,What is the advantage of using natural fertilizer?,* Reduce diseases in crops and help them grow strong and healthy. * Make the soil richer in minerals and so more fertile. * Besides, keep the air, soi

7、l and water as well as the food supply free from chemical.,Para4: Some methods to keep the soil fertile.,How many methods are mentioned in this paragraph? And what are they? 2.What is the same goal of these different organic farming methods?,The methods to keep the soil fertile 1 using natural waste

8、 from animals as fertilizer. 2 changing the kind of crop in each field every few years. 3 planting crops to use different levels of soil 4 planting grass between crops to prevent ,The same goal : _ _ _,to grow good food and avoid damaging the environment or peoples health.,Main idea of the passage,_

9、 fertilizers can cause many problems, so organic farming is becoming more_.,Chemical,popular,para1: A new discovery of scientists. para2: Several problems caused by using chemical fertilizers. para3: The advantages of using organic farming. para4: Some methods to keep the soil fertile.,The structure

10、 of this passage,Para1 Topic,Para2 Problems,Para3 Advantages,Para4 Several methods,illustration（阐明） comparison conclusion,The type of the article is_,exposition（说明文）,请以“PLASTIC OR CLOTH BAGS?”为题模仿这篇文章的篇章结构和句子结构去写一篇说明文。,Discussion and practice,Plastic Or Cloth Bags?,illustration（阐明） comparison conclu

11、sion,Para1: Para2: Para3: Para4:,Have a brief illustration of the present situation. The problems caused by using plastic bags. The advanages of using cloth bags. Conclusion.,Over the past half century, have become very common . welcomed them as a way to . Recently, however, we have been finding tha

12、t they can cause damage to , even , to peoples health. What are some of the problems caused by ? First, With these discoveries, are beginning to turn to . .,The following words may help you.,Over the past half century, plastic bags have become very common in our daily life. We welcomed them as a con

13、venient way to carry goods. Recently, however, we have been finding that they can cause damage to the environment, even worse, to peoples health.,What are some of the problems caused by plastic bags? First, people often leave plastic bags here and there, making white pollution. Second, it takes a lo

14、ng time, more than 100 years ,to be exact, to break up .Last but not least, when heated, plastic bags can produce something harmful, which can build up in our body and eventually lead to cancer or other diseases.,With these discoveries, we are beginning to turn to cloth bags. They can be used many t

15、imes. People can save a lot of sources in this way. It is also a good idea to make some by ourselves, which is interesting. Lets use cloth bags in our daily life instead of plastic bags, not only for the environment protection, but also for the sake of our health.,Suppose you were given a farm. What

16、 would you like to grow or raise? How would you deal with your farming?,Language points,1.over/in the past half century 在过去的半个世纪里,2. cause damage to 对造成伤害,3. even more dangerous 甚至更危险的是,4. wash off 冲洗掉,5.These chemicals in the food supply build up in peoples bodies over time.,supply. 用作名词时： a) 指“供给;

17、供应”等 supply and demand 供与求 be in short supply 供应缺乏,供应不足 food supply 食物供应 water supply 供水,2) 用作动词时,指“供给,提供,备办”等, supply sb._ sth , sth._ sb.,with,to /for,offer,provide sth _ sb sb _ sth,to,for,with,sth _ sb sb _ sth,When I meet difficulty, my roommates will_me help.,offer,The government need to _ foo

18、d and clothes for these old people,provide,All the rooms are _ with electric lights. A. supplied B. given C. offered D. burnt,6. build up 逐渐积聚; 增进，增强,来往的车辆在通往市区的路上越聚越多。,Traffic is building up on roads into the city.,build up ones health/body 增强体质,锻炼身体,7. lead to (leadledled ) 通向;导致（某种）结果；造成,This roa

19、d leads to the railway station.,His mistakes led to his failure.,All roads lead to Rome. 条条大路通罗马,8.in addition (to) 除之外;此外;并且,We met some friends and other people _ _. _ the killed and wounded, many were missing. _, I want to tell you something about Tom.,in,In addition to,In addition,addition,in ad

20、dition 常放在句首,用逗号隔开,或放在句末. in addition to后面常跟名词或名词短语,9.They focus on keeping their soil rich and free of disease.,focus on : 集中（注意力、精力）于,把注意力集中在你工作上.,Focus your attention on your work.,All eyes were focused on him.,10.keepfree of /from: protect. from 使免受（影响,伤害等）,健康饮食和锻炼使你远离感冒。,Healthy eating and good exercise keep you fr