Unit 5 Evaluate chemical farming and organic farming 预习ppt课件 -（2019）新人教版高中英语选择性必修第一册.pptx

1、Unit 5 Working the land Evaluate chemical farming and organic farming 预习课件预习课件 essential adj. 及其重要的；完全必要的 教材原句教材原句 There is usually more water than essential minerals. 要点必记要点必记 essential information 重要信息 essential use 必要用途 essential mineral 主要矿物 核心词汇核心词汇 alternative n. 可供选择的事物；adj. 可供替代的 教材原句教材原句 As

2、 an alternative, some farmers have switched to organic farming. 要点必记要点必记 alternative method 替代的方法 alternative approach 变换方法 have no alternative but v. 别无选择；只得；唯一的办法是 instance n. 现实；事实 教材原句教材原句 For instance, they may grow corn or wheat in a field one year. 要点必记要点必记 for instance 例如（for example; such a

3、s） in this instance 在此情况下 at the instance of 在的请求下；经的提议；因的主张 depth 轮流；依次 教材原句教材原句 Organic farmers also plan diverse crops that use different depths of soil to help keep it rich. 要点必记要点必记 in depth 深入地；全面地 in the depth of 在里面 longlength widewidth highheight deepdepth entirely v. 消化；领会 教材原句教材原句 Some pe

4、ople would prefer to stop the use of man-made chemicals in agriculture entirely. 例句例句 Their price depended almost entirely on their scarcity. 他们的价格几乎完全靠他们的供不应求。 This administration is not entirely free of suspicion. 这届政府并不是完全没有疑点。 not onlybut also 要点必记要点必记 1. not onlybut also就近原则就近原则 连接两个主语时，要和与其最近的

5、主语保持人称和数的一致。 如： Not only Tom but also Alice and Mary are busy. 不仅汤姆很忙，爱丽丝和玛丽也很忙 核心句式：核心句式： 为了强调，可将为了强调，可将not only置于句首，其后的句子通常要用置于句首，其后的句子通常要用部分倒装的形式部分倒装的形式。 如: Not only has she been late three times, she has also done no work. 她不仅仅迟到了3次，她还没干一点活。 Unit 5 Working the land Evaluate chemical farming and

6、organic farming 1 Learn more about the advantages and disadvantages of chemical farming and organic farming. Words: digest; essential; mineral; alternative; grocery; depth; root2 Phrases: for instance3 Goals Look and discuss What is the advantages and disadvantages of chemical farming? Lead in Learn

7、 Read the text and answer the question. 1. Why did many farmers welcome the introduction of chemical farming? 2. What concerns many people about the use of pesticides? 3. What is one problem with the use of chemical fertilisers? It is a great way to fight crop disease and increase production. It may

8、 make them ill and even cause cancer. Crops grow too fast to be rich in nutrition. Learn 4 How is organic farming different from chemical farming? 5 Why do organic farmers change the kind of crop grown in a field every year? 6 What is the goal of using organic farming methods? Organic farming is wit

9、hout any chemicals. They put important minerals back to the soil To grow good food without damage the environment of peoples health. Learn 2. Match the main ideas (A-D) below with the paragraphs. Then complete the sentences in the table. A What organic farming is? B Why man-made chemicals are still

10、used in farming? C Organic methods for producing rich soil? D The problems with chemical farming? Paragraph Main Idea 1-2 3 4 5 Learn D B A C Detail Pesticides can kill helpful_. Some pesticides have been _ because of the_ crops grown with chemical fertilisers usually _ to full of_. Many organic far

11、mers use _ as fertiliser. They often _ grown in each field_. They also plant crops that use _ of the soil to help keep it rich. Organic farming is nowhere near able to meet the need bacteria and insects damageprohibited nutritions grow too fast natural waste corn or wheatone year different depths Le

12、arn 3. Write an argumentatives essay giving your opinion on chemical or organic farming. Discuss these questions in groups. Is the author of the passage for or against organic farming? How do you know? What other disadvantages of chemical farming did the author not list? How might the following item

13、s be problems and how important are they for organic farming? natural animal waste used as fertiliser higher cost of producing food greater effort required to farm What other disadvantages of organic farming can you think of? Decide whether your group supports chemical farming or organic farming. Co

14、me up with three main points to support your opinion, and then add at least one detail to support each main point. Complete the outline below. In my opinion, _ farming is preferable to _ farming because (Detail) (Detail) (Detail) Learn organicchemical Keep soil rich Free of diease Rich in minerals U

15、se this checklist to help you review your partners draft. Does the writer do a good job of expressing his/her opinion? Does each paragraph have one main idea? Does each paragraph have at least one detail to support its main idea? Does the writer sequence the points in a logical order? Does the write

16、r do a good job persuading you to accept his/her opinion? Learn Summary PhrasesWords Phrases: in turn Words: digest; essential; mineral; alternative; grocery; depth; root 预习 Unit 5 Review the whole unit。3 1 Recite new words and phrases. 2 Write an article about whether we should use chemicals in farming. Homework Bye-bye!