人教版高一Unit 19 Modern agriculture
金线莲的功效与作用Ⅰ.Teaching Goals:
1.Talk about modern agriculture and the effects it has on people's life.
2.Practi giving advice and making decisions.
3.U “It” for emphasis.
4.Read statistical graphs.
5.Write a plan for a vegetable garden.
Ⅱ.Teaching Time:
Five periods
Ⅲ.Background Information:
显卡驱动怎么装1.An American Small Farm
勇敢Last year,at harvest time,we visited the Steenhoek farm,which is 2 200 mu,or 340 acres.Typical family farms are run entirely by family members,with every member playing a vital part in the operation.Both of the families are descendants of Dutch immigrants who ttled here over a century ago.
The Steenhoek farm supports 3 generations.The family of Mr.and Mrs.Steenhoek includes three children and 2 grandchildren.As we will e,this family is an excellent example of hardworking,experienced farmers who stay on the land not purely becau of profit,but becau they are living a life-style that satisfies them.Sixty percent of the Steenhoek's acres are devoted to pasture land,on which they rai 120 beef cattle.The rest of the land is ud for growing corn.
Fifteen years ago,the American farm economy was booming.Farmers could specialize,raising one crop,or one type of animal.Today,with an uncertain farm economy,such an idea is considered foolhardy,and diversifying is one way that farmers can lesson their risk of loss.For example,if weather affects the size of a crop,the sale of th
e livestock will make up the difference.If the animals are plagued by dia,at least there is grain to take to market.
Kendall Steenhoek,Simon's eldest son,divides his time between running this machine shop and farming zoo acres of corn.He attended a community college in Iowa for two years to study diel mechanics.Then he opened this repair shop for farm machinery.Kendall also plants and harvests over 30 000 bushels of corn each year,but it is the income from the repair shop that has enabled him to stay within the farming community.The heavy equipment ud on the farms today is in constant need of maintenance,and requires precision tooling for repairs.By far,the most impressive and certainly the most costly piece of farm equipment ud on a small farm is a harvesting machine called a combine,which can cost up to $100 000.
This type of machinery is what makes the American farm so efficient.With a combine,one man and his family can harvest an entire crop of a 500 acre farm in two weeks.The value of the combine is that it performs veral functions.As it moves through a field of corn,this
sophisticated machine cuts the stalk,plucks the ear,discards the stalk,shucks the corn kernels off the ear and deposites the kernels in a storage bin in the back.Then,a spinning device in the rear of the combine shreds the husks and shafts and scatters them across the field,to rve as mulch,cutting down on the possibility of soil erosion from winter rains.The machine is even more amazing when you think that it has been in u on American farms for only one generation.
2.Genes
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Every living cell contains genes.They are too small to be en in a microscope,but they are vitally important.Each t of genes in the body contains all the instructions needed to make a human being.Some genes determine hair color.Some determine the shape of a no.Some genes help determine your height and even your weight.
心理素质测试题Genes are made of a chemical called DNA-the letters stand for deoxyribonucleicacid(脱氧核糖核酸).In the early 1950's,two scientists,Francis Crick and James Watson,figured out how the parts of DNA fit together.Once scientists understood this structure,it became
possible to take pieces of DNA apart and put them together in new ways.New kinds of genes could be made in this manner.
Scientists have studied the genes of many plants and animals.They have worked out which genes affect the color of a tomato and the stickness of its skin.Working out which genes determine which features is called genetic mapping,scientists have begun the Human Genome Project,an ambitious effort to map all the genes in the human body.
Some genes may be effective.For example,something might be wrong with the gene that makes blood clot(凝聚).An individual born with this defective gene could suffer rious hemorrhages(出血)or even bleed to death becau his or her blood fails to clot.If scientists ever learn how to map all the genes in our bodies,they could determine whether or not an unborn child has any defective genes.They might even discover how to treat the genes before the child is born.
The First Period
Teaching Aims:
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1.Improve the students' speaking ability by practising giving advice and making decisions.
2.Enable the students to master the expressions of giving advice and making decisions.
3.Get the students to learn more about agriculture.
Teaching Important Points:
1.How to express onelf,using what is learned or given.
2.How to do something and how to make decisions.
Teaching Difficult Points:
学校体育工作总结
1.The usage of some expressions.
2.How to improve the students' listening ability.
Teaching Methods:
1.Listening some materials to improve the students' listening ability.
2.Discussion to let the students express themlves freely.
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3.Group work or pair work to give every student a chance to express themlves.
Teaching Aids:
1.a tape recorder
2.a projector and some slides
3.a computer
