Words previewchemicalproductionbacteriapestnutritionmineraladj. 化学的；关于化学的n. 生产；制造n. 细菌n. 害虫；害兽；害鸟n. 营养；滋养；食物n. 矿物；矿石discoveryfocussoilreducerootn. 发现；发觉 n. 焦点；中心点 vt. 集中；聚焦 n. 土壤 vt. 减少；减缩 n. 根；根源Words previewskim underlinesummarycommentvt. 浏览；略读vt. 画底线标出；强调n. 总结；摘要；概要n. 评论；议论vi.做出评论Words previewExpressions previewbuild uplead tofocus on keep free from/of逐渐增强; 建立; 开发导致; 造成 (后果) 集中 (注意力，精力等) 于使免受(影响，伤害等)；使不含(有害物)Organic FarmingWhat are genetically-modified foods? The term GM foods or GMOs (genetically-modified organisms) is most commonly used to refer to crop plants created for human or animal consumption using the latest molecular biology techniques. What are some of the advantages of GM foods? The world population has topped 6 billion people and is predicted to double in the next 50 years. Ensuring an adequate food supply for this booming population is going to be a major challenge in the years to come. GM foods promise to meet this need in a number of ways:1).pest resistance 2).disease resistance 3).cold tolerance 4).drought tolerance/salinitytolerance5).nutritionWhat are some of the criticisms against GM foods? Most concerns about GM foods fall into three categories: environmental hazards, human health risks, and economic concerns.Read and answer:What is the main idea of this passage?This passage tells us something about organic farming. It means growing crops without chemical fertilizers which damage the soil. The organic farmers keep the soilrich and healthy in several ways. 1 Why are chemical fertilizers so popular in farming today? 2 What problems can be caused by usingchemical fertilizers? 3 What is organic farming? 4 What is the main reason for usingorganic farming methods? Read the passage and answer the following questions.1 Why are chemical fertilizers so popular in farming today? They are a great way to stop crop disease and increase production.2 What problems can be caused byusing chemical fertilizers? They can damage the land by killing helpful bacteria and pets and by staying in the ground and underground water for a long time, They damage peoples health by building up in their bodies and leading to cancer or other illnesses.3 What is organic farming?4 What is the main reason for using organic farming methods? Organic farming means growing crops without using any chemicals.The main reason for using organic farming methods is to grow good food and to avoid damaging the environment or peoples health. Find and write down the methods and advantages in the passage. Methods of organic farmingAdvantages of methods Farmers use natural waste from animals.This makes the soil richer in minerals and so more fertile.Methods of organic farmingAdvantages of methods 1 Farmers use natural waste from animals.1 This makes the soil richer in minerals and so more fertile. 2 Farmers often change the kind of crop in each field every few years.2 Changing the crops renews the minerals in the soil and helps it become rich and healthy.Methods of organic farmingAdvantages of methods 3 Farmers plant crops with different lengths of roots.3 This uses different levels of soil. 4 Farmers sometimes plant grass between crops and leave it in the ground.4 This prevents wind or water from carrying away soil and acts as a natural fertilizer.Language points1 These chemicals in the food supply build up in peoples bodies over time.build up 增强; 建立；开发 Hard working conditions build up character. 艰苦的工作条件能磨练人的性格。2 Many of these chemicals can lead to cancer or other illnesses. lead to: 导致；造成 Too much work and too little rest often lead to illness.过量的工作和过少的休息会引起疾病。 All roads lead to Rome. 条条大道通罗马。3 They focus on keeping their soil rich and free of disease.focus on:集中(注意力，精力等）于You should focus your attention onyour work. 把注意力集中在你的工作上。Olympus: Focus on life. 奥林巴斯：瞄准生活。 4 This also keeps the air, soil, water and crops free from chemicals.keeps free from /of: 使免受（影响，伤害登）；使不含（有害物） keep from: 阻止; 妨碍 I hope you will keep from doing anything rash. 我希望你不要做出任何鲁莽的事情来。 Listening chemical fertilizer cow dung用化学肥料和有机肥料的区别:The possible bad effects of chemical fertilizers on the fruit and vegetablesthat we eat today.As you listen to this dialogue, keep in mind what you have just read about chemical fertilizers. What is the main topic of the conversation?Listen to the dialogue a second time. Decide if the following statements are true or false, according to the conversation. Give your reasons.1 Paul thinks that Carrie is not tellinghim the truth. 2 Using chemical fertilizers always makes vegetables empty inside.TrueFalse3 Todays fruit is not as healthy for people as fruit fifty years ago.4 Eating more vegetables might notalways be good for us.5 All of todays vegetables look healthy but in fact are not.FalseTrueTrueListening text WHATS WRONG WITH THE VEGETABLES? Girl: Hey, Paul, listen to this a magazine article about a farmerwho used too much chemicalfertili