人教版必修4Unit2 Using language Reading 課件

1、Unit 2 Using languageReadingChemical or organic farming?Words preview chemical production bacteria pest nutrition mineral adj. 化學(xué)的；關(guān)于化學(xué)的化學(xué)的；關(guān)于化學(xué)的n. 生產(chǎn)；制造生產(chǎn)；制造n. 細(xì)菌細(xì)菌n. 害蟲；害獸；害鳥害蟲；害獸；害鳥n. 營(yíng)養(yǎng)；滋養(yǎng)；食物營(yíng)養(yǎng)；滋養(yǎng)；食物n. 礦物；礦石礦物；礦石 discovery focus soil reduce root n. 發(fā)現(xiàn)；發(fā)覺發(fā)現(xiàn)；發(fā)覺n. 焦點(diǎn)；中心點(diǎn)焦點(diǎn)；中心點(diǎn)vt. 集中；聚焦集中；聚焦n. 土壤土壤v

2、t. 減少；減縮減少；減縮n. 根；根源根；根源Words preview skim underline summary comment vt. 瀏覽；略讀瀏覽；略讀vt. 畫底線標(biāo)出；強(qiáng)調(diào)畫底線標(biāo)出；強(qiáng)調(diào)n. 總結(jié)；摘要；概要總結(jié)；摘要；概要n. 評(píng)論；議論評(píng)論；議論vi.& vt. 表達(dá)意見表達(dá)意見; 做出評(píng)論做出評(píng)論Words preview Expressions preview build up lead to focus on keep free from/of逐漸增強(qiáng)逐漸增強(qiáng); 建立建立; 開發(fā)開發(fā)導(dǎo)致導(dǎo)致; 造成造成 (后果后果) 集中集中 (注意力，精力等注意力，精力等) 于

3、于使使免受免受(影響，傷害等影響，傷害等)；使使不含不含(有害物有害物) 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 th

4、e 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:First

5、 reading ( 3ms ) Read the passage on page14 , then find out the main idea of each paragraph.Para 1: Para 2:Para 3:Para 4: Long-term use of fertilizers can cause damage to the land and people s health.The problem caused by chemical fertilizers .Some farmers and many customers are beginning to turn to

6、 organic farming.Organic farmers also use many other methods to keep the soil fertile. Second reading ( 5ms )Read the text again and answer the following questions:1 Why are chemical fertilizers so popular in farming today?2 What problems can be caused by using chemical fertilizers ?3 What is organi

7、c farming ?4 What is the main reason for using organic farming methods ?1.Why are chemical fertilizers so popular in farming today ?They can stop crop disease and increase production.2 What problems can be caused by chemical fertilizers ?There are three problems. First, chemical fertilizers affect t

8、he soil and the water supply badly. Second, they allow farmers to grow the same crop year after year and exhaust the soil. Third, they kill both helpful and harmful pests. Organic farming is simply farming without using any chemicals .3 What is organic farming ?4 . What is the main reason for using

9、organic farming methods ?A healthy soil reduces disease and helps crops grow strong and healthy .Third reading ( 8ms )Read the text again, and fill in the following forms.Methods of organic farmingAdvantages of methods1 Farmers use natural waste from animals.1 This makes the soil richer in minerals

10、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 methods3 Farmers plant crops with different lengths of roots.3 This uses differe

11、nt 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.What is the disadvantage of using chemical fertilizers?1.Leaving chemicals in the ground for a long time is not good for t

12、he soil or the water supply.2.Farmer often grow the same crop year after.As a result, the soil gets exhausted.3.Chemical fertilizers kill both helpful and harmful bacteria and pests.Retelling ( 8ms )Retell the text according to the chart: Organic farmingI. Crops growing with natural fertilizers.II.

13、Farmers prefer natural waste from animals.Natural fertilizerChemical fertilizer1.makericher and more fertile2.reduceand help strong3.the fertilizers killand healthy4.keep freefrom chemicals1.leavingis not good2.growyear after yearIII. Farmers change crops every two or three years. to make sure what

14、is left Language points1 These chemicals in the food supply build up in peoples bodies over time.build up 增強(qiáng)增強(qiáng); 建立；開發(fā)建立；開發(fā) Hard working conditions build upcharacter. 艱苦的工作條件能磨練人的性格。艱苦的工作條件能磨練人的性格。 2 Many of these chemicals can lead to cancer or other illnesses.lead to: 導(dǎo)致；造成導(dǎo)致；造成Too much work and to

15、o little restoften lead to illness. 過量的工作和過少的休息會(huì)引起疾病過量的工作和過少的休息會(huì)引起疾病。All roads lead to Rome. 條條大道通羅馬。條條大道通羅馬。3 They focus on keeping their soil rich and free of disease.focus on:集中集中(注意力，精力等）于注意力，精力等）于You should focus your attention on your work.把注意力集中在你的工作上。把注意力集中在你的工作上。 Olympus: Focus on life.奧林巴斯

16、：瞄準(zhǔn)生活。奧林巴斯：瞄準(zhǔn)生活。 4 This also keeps the air, soil, water and crops free from chemicals. keeps free from /of: 使使免受（影免受（影響，傷害登）；使不含（有害物）響，傷害登）；使不含（有害物）keep from: 阻止阻止; 妨礙妨礙 I hope you will keep from doinganything rash. 我希望你不要做出任何魯莽的事情來。我希望你不要做出任何魯莽的事情來。 5Recently ,however , scientists have been finding

17、 that long-term use of these fertilizers can cause damage to the land and , even more dangerous , to peoples health然而最近,科學(xué)家們發(fā)現(xiàn)長(zhǎng)期使用化肥會(huì)給土地造成損害,甚至更危險(xiǎn)的是會(huì)給人類的健康造成損害.1 (1)however為副詞, 意為”然而，可是 ”，表轉(zhuǎn)折，可用于句首,句末,句中,如在句中,起前后都要加逗號(hào).例如: He , however ,couldnt pay for the education that young Albert needed . 然而,他無法支

18、付小艾伯特的教育費(fèi)用(2)however為連詞,引導(dǎo)讓步狀語(yǔ)從句,相當(dāng)于相當(dāng)于no matter how ,修飾形容詞或副詞.例如:However hot it is , he will never take off his coat .=No matter how hot it is , he will never take off his coat . 無論多么熱,他都不會(huì)把外套脫掉.However fast you run , you cant catch up with a car .=No matter how fast you run , you cant catch up wit

19、h a car . 無論你跑得多快,你也趕不上一輛小汽車.2. have been finding 是現(xiàn)在完成進(jìn)行時(shí),現(xiàn)在完成進(jìn)行時(shí)的特點(diǎn)是強(qiáng)調(diào)”動(dòng)作的連續(xù)性”,但有可能已經(jīng)終止.例如:He is very tired , he has been working hard all day . 他很累,他整天都在努力工作.He has been writing a letter. 他一直在寫信.6They often change the kind of crop in each field every few years ,他們通常每隔幾年就改變一塊田地里作物的種類,every 或 “ever

20、y other+時(shí)間”表示”每隔每”,表示時(shí)間或空間的間隔. 具體用法是 : “every+基數(shù)詞基數(shù)詞+復(fù)數(shù)復(fù)數(shù)名詞”;”every +序數(shù)詞序數(shù)詞+ 單數(shù)名詞單數(shù)名詞”.例如:every year 每年every two years / every second year / every other year每?jī)赡?每隔一年)every three years / every third year /every other two years .每三年(每隔兩年)every four years / every fourth year / every other three years 每

21、四年(每隔三年)7Why are chemical fertilizers so popular in farming today ?為什么花費(fèi)在現(xiàn)在的耕作中如此受歡迎?popular 的用法:(1)popular 為形容詞,意為”受喜愛的，受歡迎的，當(dāng)紅的”. 常用短語(yǔ): be popular with sb 受某人歡迎. 例如:This is one of our most popular designs . 這是我們是受歡迎的設(shè)計(jì)之一.Skiing has become very popular recently . 滑雪運(yùn)動(dòng)最近盛行起來.Im not very popular with

22、 my parents at the moment . 眼下爸媽對(duì)我很不高興.(2)popular 為形容詞,意為”通俗的,大眾化的”.例如:popular music / culture / fiction 流行音樂/文化/小說popular 為形容詞,意為”(概念,信仰,意見)普遍的，大眾的，流行的”. 例如:Contrary to popular belief, women cause fewer road accidents than men . 與普遍的看法相反,婦女交通肇事比男人少. avoid doing sth.避免做某事prefer doing sth.寧愿做某事寧愿做某事prevent from使使免受免受1. What made Jia Sixie become interested in improving Chinese farming? He saw how some farms produced good crops and healthy animals and others did not.Reading task on Page 52 ( 15ms)Read the passage on Page 52, then finish the exercises on Page 53.2. How d