浙江省诸暨市草塔中学高中英语（人教版）必修4课件：UNIT 2 USING LANGUAGE.ppt

1、 What is the substance we put on the soil which makes crops grow?It is fertilizer.How many kinds of fertilizers do farmers use?There are two kinds.They are chemical fertilizers and natural ones.zxxk Which kind do farmers use when they are doing organic farming?Do you know about organic farming?ORGAN

2、IC FARMINGOrganic farming is simply farming without using any chemicals.1.Why are chemical fertilizers so popular in farming today?I.Read the passage and answer the following questions.They are a great way to stop crop disease and increase production.2.What problems can be caused by using chemical f

3、ertilizers?They can damage the land by killing helpful bacteria and pests 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?Organic farming means growing crop

4、s without using any chemicals.4.What is the main reason for using organic farming methods?The main reason for using organic farming methods is to grow good food and to avoid damaging the environment or peoples health.II.Read the text again and fill in the blanks.Chemical FarmingAdvantages Stopping c

5、rop disease and increase _productionChemical FarmingDisadvantagesDamaging the land:killing the helpful _ Damaging peoples health:Many chemicals in the food supply can lead to cancer or other illnesses.Food grows too fast to be full of much _.bacteria and pestsnutritionOrganic farming_To grow good fo

6、od and avoid damaging the environment or peoples health z/xxkGoalOrganic farmingMethods Using _ waste from animals as fertilizerChanging _ in each field every few years Using _ of soil to plant crops Planting _ between cropsgrassnaturalthe kind of cropdifferent levelsIn what condition do you think g

7、reen food grow?The advantages of green fooddirty air dirty water supplies in industrial areas many chemical fertilizersclean,fresh air clean water supplies away from industrial areas free of chemical fertilizersMain idea of the passageChemical fertilizers can cause many problems,so organic farming i

8、s becoming more popular.ORGANIC FARMINGStructure of the textI using chemical fertilizers for a long time can hurt the land and also peoples healthII Problem caused by chemical fertilizers1.Damage the land by killing the helpful bacteria and pests as well as the harmful ones2.Lead to cancer or other

9、illness.3.Food grown with chemical fertilizers look beautiful,but inside there is usually more water than vitamins and minerals.Organic farming is becoming more popular with some farmers and many customers after these discoveries came out.IV Other methods to keep the soil fertile.ProjectPersuade the

10、 farmers in our county to grow the crops by organic farming with the knowledge learnt.What is organic farming?What fertilizer should they use?Why?How to plant the different crops?Language points1.lead to用法寓词于境 阅读下列句子，注意lead to的意思和用法。1.His carelessness led to the accident.2.This test is obviously bad

11、 because it leads to incorrect learning.3.Too much work and too little rest often leads to illness.自我归纳 lead to意为“_”,后多跟名词或代词。导致、造成(后果)联想 result in引起(某种结果)、使获得(某种成果)、结果。如：The accident resulted in two deaths.result from由造成、因而产生。如：Sickness sometimes results from eating too much.即学即练 用lead to的适当形式完成句子。

12、1.Students should always remember that hard work is the main way which _ success.2.The bad weather _ a terrible accident a few days ago.led toleads to2.focus用法根据语境推断focus在下列句子中的含义,并从a-d中找出与每句话中的focus相符合的英文释义。1.The focus of the meeting changed from population growth to the education of women.2.Bring

13、the object into focus if you want a clear photograph.3.She tried to focus her mind on her work.4.She turned the camera and focused on Martins face.a.the thing,person,situation,etc.that people pay special attention tob.a point or distance at which the outline of an object is clearly seen by the eye o

14、r through a lensc.to point a camera at something,and change the controls slightly so that you can see that thing clearly d.to give special attention to one particular person or thing,or to make people do thiscabdfocus作名词,意为“焦点、中心点”;作动词,意为“集中、聚焦”,常构成短语focus on,意为“集中(注意力、精力等)于”。翻译下列句子。1.Because of his

15、 strange clothes,he immediately became the focus of attention when he entered the office.由于他的奇装异服,所以一走进办公室他便成了大家注意的焦点。2.Focus your camera on those trees.3.Im so tired that I cant focus on anything today.把照相机的焦点集中在那些树上。今天我太累了,精神集中不起来。3.keep free from “远离”或“避免”keep free from emotional reactions 避免激动的反

16、应keep free from restrictions 避免受到限制4.Crops such as peas or soybeans put important minerals back into the soil,making it ready for crops such as wheat or corn that need rich and fertile soil.分析 本句结构比较复杂。其主干结构为:主句(Crops put important minerals back into the soil)+状语(making it ready for crops)。状语中又包含“ma

17、ke+it+形容词”结构和由that引导的定语从句(that need rich and fertile soil)。5.Some organic farmers prefer planting grass between crops to prevent wind or water from carrying away the soil,and then leaving it in the ground to become a natural fertilizer for the next years crop.分析本句的主干结构是一个简单句,其结构是:主语(farmers)+谓语(pref

18、er)+并列宾语(planting.+leaving.)。其中between crops和in the ground作地点状语。两个宾语后面又分别带有一个不定式作目的状语（to prevent wind or water from carrying away the soil和to become a natural fertilizer for the next years crop）。What is the main topic of the conversation?The possible bad effects of chemical fertilizers on the fruit

19、and vegetables that we eat today.1.Paul thinks that Carrie is not telling him the truth.2.Using chemical fertilizers always makes vegetables empty inside.3.Todays fruit is not as healthy for people as fruit fifty years ago.4.Eating more vegetables might not always be good for us.5.All of todays vegetables look healthy but in fact are not.T or F.T FT FT Collect some information about the safety and importance of green food.