人教版必修四英语第二单元Using-Language精品课件

B4U2Whatisthesubstanceweputonthesoilwhichmakescropsgrow?Itisfertilizer.Howmanykindsoffertilizersdofarmersuse?Therearetwokinds.Theyarechemicalfertilizersandnaturalones.Whichkinddofarmersusewhentheyaredoingorganicfarming?Doyouknowaboutorganicfarming?ORGANICFARMINGOrganicfarmingissimplyfarmingwithoutusinganychemicals.1.Whyarechemicalfertilizerssopopularinfarmingtoday?Readthepassageandanswerthefollowingquestions.Theyareagreatwaytostopcropdiseaseandincreaseproduction.2.Whatisorganicfarming?Organicfarmingmeansgrowingcropswithoutusinganychemicals.3.Whatisthemainreasonforusingorganicfarmingmethods?Themainreasonforusingorganicfarmingmethodsistogrowgoodfoodandtoavoiddamagingtheenvironmentorpeople’shealth.Readthepassagecarefullyandfillintheblanks.ChemicalFarmingAdvantagesStoppingcropdiseaseandincrease__________productionChemicalFarmingDisadvantagesDamagingtheland:killingthehelpful________________Damagingpeople’shealth:◆Manychemicalsinthefoodsupplycanleadtocancerorotherillnesses.◆Foodgrowstoofasttobefullofmuch________.bacteriaandpestsnutritionOrganicfarming____Togrowgoodfoodandavoiddamagingtheenvironmentorpeople’shealthGoalOrganicfarmingMethods◆Using_______wastefromanimalsasfertilizer◆Changing______________ineachfieldeveryfewyears◆Using_____________ofsoiltoplantcrops◆Planting_____betweencropsgrassnaturalthekindofcropdifferentlevelsProjectPersuadefarmerstogrowthecropsbyorganicfarmingwiththeknowledgelearnt.Whatisorganicfarming?Whatfertilizershouldtheyuse?Why?Howtoplantthedifferentcrops?...1.Manyofthesechemicalscanleadtocancer...leadto用法[寓词于境]阅读下列句子，注意leadto的意思和用法。1)Hiscarelessnessledtotheaccident.2)Thistestisobviouslybadbecauseitleadstoincorrectlearning.3)Toomuchworkandtoolittlerestoftenleadstoillness.[自我归纳]leadto意为“_________________”,后多跟名词或代词。导致、造成(后果)[联想]resultin引起(某种结果)、使获得(某种成果)、结果……。如：Theaccidentresultedintwodeaths.resultfrom由……造成、因……而产生。如：Sicknesssometimesresultsfromeatingtoomuch.[即学即练]用leadto的适当形式完成句子。1.Studentsshouldalwaysrememberthathardworkisthemainwaywhich_______success.2.Thebadweather_____aterribleaccidentafewdaysago.ledtoleadsto2.Theyfocusonkeepingtheirsoilrichandfreeofdisease.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.Thefocusofthemeetingchangedfrompopulationgrowthtotheeducationofwomen.2.Bringtheobjectintofocusifyouwantaclearphotograph.3.Shetriedtofocushermindonherwork.4.SheturnedthecameraandfocusedonMartin’sface.a.thething,person,situation,etc.thatpeoplepayspecialattentiontob.apointordistanceatwhichtheoutlineofanobjectisclearlyseenbytheeyeorthroughalensc.topointacameraatsomething,andchangethecontrolsslightlysothatyoucanseethatthingclearlyd.togivespecialattentiontooneparticularpersonorthing,ortomakepeopledothiscabdfocusn.意为“焦点、中心点”;v.意为“集中、聚焦”常构成短语focuson,意为“集中(注意力、精力等)于”。翻译下列句子。1.Becauseofhisstrangeclothes,heimmediatelybecamethefocusofattentionwhenheenteredtheoffice.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.Focusyourcameraonthosetrees.3.I’msotiredthatIcan’tfocusonanythingtoday.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.Thisalsokeepstheair,soil,waterandcropsfreefromchemicals.keep…freefrom“远离”或“避免”keepfreefromemotionalreactions避免激动的反应keepfreefromrestrictions避免受到限制4.reducev.减少,降低e.g.公司尽力通过减少花销来提高利润。Thecompanytriestoincreaseprofitsby_______________.今年我们已经减少了业务开支。We______________expensesthisyear.reducingcostshavereduced5.Cropssuchaspeasorsoybeansputimportantmineralsbackintothesoil,makingitreadyforcropssuchaswheatorcornthatneedrichandfertilesoil.[分析]①本句结构比较复杂。其主干结构为:主句(Cropsputimportantmineralsbackintothesoil)+状语(makingitreadyforcrops)。②状语中又包含“make+it+形容词”结构和由that引导的定语从句(thatneedrichandfertilesoil)。6.Someorganicfarmerspreferplantinggrassbetweencropstopreventwindorwaterfromcarryingawaythesoil,andthenleavingitinthegroundtobecomeanaturalfertilizerforthenextyear’scrop.[分析]①本句的主干结构是一个简单句,其结构是:主语(farmers)+谓语(prefer)+并列宾语(planting...+leaving...)。②其中betweencrops和intheground作地点状语。③两个宾语后面又分别带有一个不定式作目的状语（topreventwindorwaterfromcarryingawaythesoil和tobecomeanaturalfertilizerforthenextyear’scrop）。Expressions1.化肥2.对…造成损害3.洗掉某物4.导致;造成(后果);通往5.逐渐增强,建立6.另外(还有)7.使…免受(影响);8.集中(注意力、精力)于9.每隔几年10.避免做…chemicalfertilizerscause/dodamagetowashoffleadtobulidupinaddition(to)keep…freefrom/offocusoneveryfewyearsavoiddoing