高一英语必修4 Unit 2.ppt

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1、Unit 2 Working the land,Task 1:Brainstorming,What will you think of when you see the word“agriculture”?,agriculture,farm,irrigation,food,crop,field,plants,plain,GMF,grain,farmer,fertilizer,seed,prairie,countryside,land,arableland,agriculture,wheat,corn,rice,soybean,cotton,broomcorn,peanut,Terrace,Dr

2、ought,Irrigated land,Greenhouse,In the first picture:,*Terraced fields.,In the second picture:,*Dry barren farmland.,In the third picture:,*Irrigated farmland.,In the fourth picture:,*Greenhouses.,What are the differences?Compare the old and the modern ways of irrigation.,in bad weather,crops lost,c

3、limate controlled,less damage,The landscape loses its natural beauty.,Only arable land can grow crops.,Greenhouses can be built almost everywhere.,The landscape is more beautiful.,If there is a power failure,you may lose crops.,What are genetically-modified foods?The term GM foods or GMOs(geneticall

4、y-modified organisms)is most commonly used to refer to crop plants created for human or animal consumption using the latest molecular biology techniques.These plants have been modified in the laboratory to enhance desired traits such as increased resistance to herbicides or improved nutritional cont

5、ent very rapidly and with great accuracy.For example,plant geneticists can isolate a gene responsible for drought tolerance and insert that gene into a different plant.The new genetically-modified plant will gain drought tolerance as well.,What are some of the advantages of GM foods?The world popula

6、tion 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

7、tolerance 4).Drought tolerance/salinity tolerance5).Nutrition Thirteen countries grew genetically-engineered crops commercially in 2000,and of these,the U.S.produced the majority.In 2000,68%of all GM crops were grown by U.S.farmers.In comparison,Argentina,Canada and China produced only 23%,7%and 1%,

8、respectively.Soybeans and corn are the top two most widely grown crops(82%of all GM crops harvested in 2000),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.,Every eight seconds,a

9、child somewhere in the world dies from starvation.More than 6 million children under the age of 5 die from starvation every year.More than 800 million people in the world suffer from chronic malnutrition799 million of them are from the developing world.More then 153 of them are under the age of 5.,S

10、ome 700,000 Central Americans are suffering from hunger today,including 6,000 children at risk of staring to death.,Discussion:What will you think after reading the following facts?,Reading:Is Yuan Longping more of a scientist than a farmer?What are Yuan Longpings achievements?What were his dreams a

11、nd how far did he achieve them?,Gerund 动名词1.Usagea.Climbing mountains is hard work.(Its hard work climbing mountains.)主语She enjoys acting.b.Thank you for telling me the truth.宾语c.My job is teaching.表语d.There are a lot of books in the reading room.定语e.I caught the thief stealing.宾语补足语,2.Verb.习惯上只接动名词

12、的动词admit,advise,allow appreciate,avoid,consider,delay,deny,risk,practise,finish,forbid,give up,forgive,enjoy,escape,imagine,mind,mention,suggest,put off,permit,prohibit,report可接不定式和动名词且含义相同的动词Like,love,hate,prefer,begin,start,continue,intend,attempt,bother可接不定式和动名词且含义不同的动词Remember,forget,regret,try,

13、mean,stop,go on,3.Tense现在I like collecting stamps.Would you mind closing the door?I remember bringing the book with me.b.完成He forgot having promised me to buy me a CD.Thank you for having told me the news.,4.Voice He didnt mind being called“potato”.He didnt mind caring for the baby.Notice:“need”,“wa

14、nt”,“require”,“be worth”主动表被动This coat wants washing.The task is worth doing.The bike requires/needs mending.,Words&Expressions,1.Dr.Yuan searched for a way to increase rice harvests without expanding the area of fields.The police are searching for the murderer.The police are.,in,of,search,expand:to

15、 become larger in size 增大The population of China expanded quickly in the 1960s.You can expand your knowledge by reading more books.expansion n.expandable adj.,2.Dr.Yuan is now circulating his knowledge in India,.circulate:to move around within a system循环 became known by others交流Rumors circulated qui

16、ckly.The blood circulates around the body.circulation n.,3.Thanks to his research,the UN is trying to rid the world of hunger.thanks to:due to because ofThanks to your help,I passed the exam.Thanks to his help,Jane will be back soon.rid sb./sth.of sth.The vaccination program will rid the world of sm

17、allpox.She is trying to rid herself of a dependence on drugs.You should rid yourself of the bad habits.=You should get rid of the bad habits,4.So he gives millions of yuan to equip others for their research in agriculture.equip:to provide with thingsThe boys equipped themselves with torches and rope

18、,and set off.The emergency services are equipped to deal with disasters of this kind.We want our son to have an education that will equip him for later life.equipment n.,5.It also refers to crops growing with natural rather than chemical fertilizers.6.Putting this in their fields,they argue,makes the soil richer in minerals and so more fertile.,