人教版高中英语必修四unit2_Using_language_优质课课件

1、unit 2 working the land using language,green food,organic food,chemical or organic farming?,reading,recently, however, scientist have been finding that long-term use of the chemical fertilizers can cause damage to the land and, even more dangerous, to peoples health.,what are some of the problems ca

2、used by chemical fertilizers?,find out and underline the topic sentences of each paragraph.,para1.,para2.,skimming,para 3.,para 4.,with these discoveries, some farmers and many customers are beginning to turn to organic farming.,organic farmers also use many other methods to keep the soil fertile.,s

3、canning,read the passage,and answer the questions.,1. how many problems can be caused by using chemical fertilizers?,2. what are the advantages of organic farming?,3. which one isnt the method to keep the soil fertile?,1. how many problems can be caused by using chemical fertilizers?,first, they can

4、 damage as well as . chemicals also stay in the and . in addition, grow too fast to .,there are three problems.,2. what are the advantages of organic farming? the farmers _ keeping their soil rich and free of disease and _ the air , soil, water and crops _ chemicals.,focus on,keeping,free from,3. wh

5、ich one isnt the method to keep the soil fertile? a. using natural waste from animals as fertilizer. b. changing the kind of crop in each field . c. planting crops to use the same level of soil. d. planting grass between crops to prevent wind or water from carrying away the soil.,para1. a new discov

6、ery 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 of this passage,topic (present situation),problems,advantages,methods (conclusion),the type of the article is_,

7、exposition（说明文）,consolidation,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 writing,discussion and writing,plastic or cloth bags?,para1. para2. para3. para4.,have a brief illustration of the present situation. the problems caused by using plastic bags. the advantages of using c

8、loth bags. conclusion.,problems： 1. cause white pollution 2. easy to be broken 3. difficult to break down 4. do harm to the environment and peoples health advantages： 1. can be recycled and reused 2. save resources 3.cheap 4. protect the environment,over the past half century, have become very commo

9、n . recently, however, we have been finding that they can cause damage to . what are some of the problems caused by ? first, with these discoveries, are beginning to turn to . .,the following words may help you.,homework : finish the writing .,thank you for attention！,over the past half century, pla

10、stic bags have become very common in our daily life. we welcomed them as a convenient 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 of all, people o

11、ften leave plastic bags here and there, making white pollution. whats more, it takes a long time, more than 200 years, 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 illnesses.,with these discoveries, we are beginning to turn to cloth bags. they can be used many times. people can save a lot of resources in this way. it is also a good idea to make some cloth bags by o