人教新课标必修四Unit2Workingtheland–Usinglanguage.pptVIP

Unit 2 Working the land Using language;; discovery focus soil reduce root ; skim underline summary comment ;; Organic Farming;What 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/salinity tolerance 5).nutrition;What 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:;1 Why are chemical fertilizers so popular in farming today? 2 What problems can be caused by using chemical fertilizers? 3 What is organic farming? 4 What is the main reason for using organic farming methods? ;1 Why are chemical fertilizers so popular in farming today? ;2 What problems can be caused by using chemical fertilizers?;3 What is organic farming? 4 What is the main reason for using organic farming methods? ;Find and write down the methods and advantages in the passage.;Methods of organic farming;Methods of organic farming;Language points;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 on your 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