浙江省天臺縣平橋第二中學(xué)高中英語 Unit 2 using language課件 新人教版必修4

Chemical Or Organic Farming? green food organic food Chemical Or Organic Farming?First reading: get the main idea of each paragraph.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.1 Why are chemical fertilizers so popular in farming today? 2 After the long-term use of chemical fertilizers, what have scientists found?Many farmers welcomed them as a great way to stop crop disease and increase production.Long-term use of chemical fertilizers can cause damage to the land and , even more dangerous, to peoples health.Recently, however, therefore; meanwhile; anyhow; thus ;otherwise; moreover; besides etc.Second readingTips: the usage of several adverbs means clear and reasonable connection between parts. Read paragraph 2 and find out the problems caused by using chemical fertilizers. There are three problems.First, they can damage as well as . They also stay in the and . In addition, grow too fast to . Tips: connectives（過渡詞）（過渡詞） and transitional phrases（過渡詞）（過渡詞） for development first;second; finally;last but not least ,etc.Read paragraph 3-4 What are the advantages of organic farming? The farmers focus on keeping their soil rich and free of disease and keeping the air , soil, water and crops free from chemicals.Tips: several phrases can be used. The methods to keep the soil fertile1 using natural waste from animals as fertilizer. 2 changing the kind of crop in each field .3 planting crops to use different levels of soil4 planting grass between crops to prevent The same goal : _ to grow good food and to avoid damaging the environment or peoples health.Tips: infinitive” to” is used to express the purpose 1 such as wheat or corn that need rich and fertile soil. 2 planting peanuts that use the grounds surface followed by vegetables that put down deep roots. Read the following sentence, and find what they have in common?Tips: clauses make the passage logical（邏輯的）（邏輯的） and beautifulNoun Clauses & Attributive ClauseThe two sentences both include attibutive clause.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 of this passagePara1 TopicPara2 ProblemsPara3 AdvantagesPara4 Several methodsillustration（闡明）（闡明）comparison conclusionThe type of the article is_exposition（說明文）（說明文）請以請以“PLASTIC OR CLOTH BAGS?”為題為題模模仿仿這篇文章的篇章結(jié)構(gòu)這篇文章的篇章結(jié)構(gòu)和句子結(jié)構(gòu)去寫一篇說和句子結(jié)構(gòu)去寫一篇說明文。明文。Discussion and practicePlastic Or Cloth Bags?illustration（闡明）（闡明）comparison conclusionPara1: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.The following words may help you.Over the past half century, have become very common . welcomed them as a way to . Recently, however, we have been finding that they can cause damage to , even , to peoples health.Homework :Finish the writing .Over the past half century, have become very common . welcomed them as a way to . Recently, however, we have been finding that 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.Para1 Topic Para2 ProblemsPara3 AdvantagesPara4 Several methodsIllustration（闡明）（闡明）comparison conclusionThe type of the article is_Exposition（說（說明文）明文）The structure of this passage zx xkOver the past half century, plastic 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, people often leave plastic bags here and there, making white pollution. Second, it takes a long 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 illnesses. With these discoveries, we are beginning to turn to cloth bags. They can be used many times. People can save a lot of source 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 the sake of our health. What do you think of the farming today? healthy? environment-friendly? natural? chemical? organic? green? transgenic?