教学课件：《新核心高职行业英语-农学英语》

Unit1HowDoesPhotosynthesisWork?I.FocusonthetopicII.VocabularystudyIIII.ReadingoneIV.Task-drivenpracticeV.Readingtwo

VII.DoItYourself(D.I.Y.)HowDoesPhotosynthesisWorkI

VIII.AchievementTest

VI.

WritingPart1FocusonthetopicSearchthelibraryortheinternetforinformationabouttheprocessofplantgrowth.Discussthenecessaryconditionsforplantgrowth.Discusstheprocessofphotosynthesiswhichyouhavelearned.Writeagroupreportandprepareforanin-classpresentation.Part2Vocabularystudy1.Readthesentences.Thencirclethedefinitionoftheboldfacedwords.(1)Thecloudsindicatethecomingofrain.Indicatemeans__________________.a.beasignalfororasymptomofb.expresssomeone’sidea(2)Letmeillustratethepointwithsomeverysimplegraphs.Whenyouillustratesomething,you__________________.a.explainitbygivinganexampleb.doitwithothermethods(3)Weshouldrestrictthenumberofstudentsinthisclassroom?Whenyourestrictsomething,you__________________it.a.givesuggestionstob.placelimitsonPart2Vocabularystudy(4)Thenwecoulddiptheclothinanycolorwewanted.Whenyoudipsomething,you__________________.a.putintoaliquidb.fixtogether(5)Ourrescueteamworkshardtosavethembytranslocatingtoanotherarea.Whensomethingtranslocates,it__________________.a.lendsahandtob.movesfromoneplacetoanother(6)Plantstakeincarbondioxideandreleaseoxygenusinglightasenergyduringphotosynthesis.Photosynthesisisthewaythat__________________.a.greenplantsmaketheirfoodusingsunlightb.greenplantsmakefoodforanimalsPart2Vocabularystudy(7)Anexamplewilldemonstratehowtheseobjectsworktogether.Whenyoudemonstratesomething,you__________________.a.provideevidenceforitb.explainit(8)Donotexposeittothesun.Exposemeans__________________.a.coversomethingb.withoutcover(9)WhenIdrinkalotofalcoholIbecomeafunnierperson.Drinkingalcoholmeansdrinking__________________.a.waterb.beer,wine,orwhiskyPart2Vocabularystudy(10)Bothsaltandsugardissolveeasilyinwater.Whensaltisdissolvinginwater,it__________________.a.becomesmixedwithwateranddisappearsb.becomesobviousPart2Vocabularystudy2.Matchthewordsintheleftcolumnwiththeirdefinitionsintherightcolumn.(1)Photosynthesisca.限制(2)dipeb.证明；论证(3)restrictac.光合作用(4)indicatehd.改变……的位置(5)illustratege.浸；泡(6)demonstratebf.酒精(7)alcoholfg.阐明(8)dissolveih.预示(9)translocate d i.溶解；分解(10)exposeto j j.暴露于Part3ReadingonePhotosynthesisThesynthesisofcarbohydrate（碳水化合物）isusuallyreferredtophotosynthesisorcarbonassimilation（碳同化）.Itoccursinallgreenplantsinsunlight[1],whichcanbereducedbytheactionofsunlightongreenplants.Inmostplants,thecompletionofthisprocessisindicatedbytheappearanceofstarchintheleaf-cells,thoughafewspeciesneversynthetizestarch.Itislikelytoproducesugarfirst,suchasglucose（葡萄糖）,butthiscannotbestored.Ithasbeengenerallyrecognizedthatthesynthesisofcarbohydratedependsonthepresenceoflight,thegreensubstancechlorophyll（叶绿素）,supplyofcarbondioxideandwater[2],togetherwithotherfactorsthatprobablyaffecttherateofsynthesisbutdonotactuallycontrolit.Anumberofsimpleexperimentscanshowhowthefactorsmentionedaffectthephotosynthesis,andforthispurposeplantswithfairlylargeandthinleaves,suchasNasturtium（旱金莲）orpelargonium（天竺葵属植物）,areveryconvenient.Part3ReadingoneItmustberememberedthatwhenexperimentsarecarriedouttoillustratecertainaspectsofaprocess,itisnecessarytoputupcontrolexperimentsasfaraspossible,whilethespecificfactorsunderconsiderationarenotrestricted[3].Inthesimplephotosyntheticexperiments,thepresenceofstarchintheleavesistakenasthecriterionthatcarbonassimilationhastakenplace,anditisthemethodthatshouldbedemonstratedthepresenceofstarchatfirst[4].Takealeaffromtheplantanddipintheboilingwatertokillit(stopanyfurtherchanges,whichmakestheremovalofthechlorophylleasier);thenputtheleafintothe90%warmethylalcohol（乙醇）whichdissolvesthechlorophyll;Washitinthewaterandthenplaceitintothediluteiodine（碘酒）.Ifstarchispresent,theleafturnsblack;andifaportionoftheleafisexamined,thestarchgrainscanbeseenunderthemicroscope.Duringtheexperiments,severalplantsareputincompletedarknessfortwentyfourhours,afterthatthesampleleavesaretestedtoseewhetheranystarchwillbeabsent.Part3ReadingoneItmaybesaidrightawaythatstarchwillbeabsent,becauseithasbeentranslocatedfromtheleaf(afterconversiontoglucose)duringthedarkperiod.Todemonstratethenecessityforlight,oneplantisexposedtonormaldaylight,preferablysunlight,fortwoorthreehours,whileacorrespondingplantisputbackintothedark，anotherwayisavailable,thatisaleafcanbecoveredwithamaskofblackpaperinwhichadesigncanbecutasastencilsothatlightcanreachthatpartoftheleaf[5].Afterexposuretolight,theexperimentalleaf(oraleaffromtheexposedplantandonefromtheplantkeptinthedark)istestedforstarchbythemethoddescribed,anditisfoundthatthelightstarchhasdisappeared.Inthecaseofthepartofthecoveredleafwillappearcolorless,whileanotherpartunderthestenciledpatternwillbedarkbecauseofthestarch.

1.Thesynthesisofcarbohydrateisusuallyreferredtophotosynthesisorcarbonassimilation.Itoccursinallgreenplantsinsunlight.碳水化合物的合成通常是指光合作用或同化作用。所有绿色植物在阳光照射下都发生这种作用。referto指的是；occur发生2.Ithasbeengenerallyrecognizedthatthesynthesisofcarbohydratedependsonthepresenceoflight,thegreensubstancechlorophyll,supplyofcarbondioxideandwater.一般认为，碳水化合物的合成依赖于光、绿色物质叶绿素、二氧化碳和水。dependon依赖于，依靠NOTES

3.Itmustberememberedthatwhenexperimentsarecarriedouttoillustratecertainaspectsofaprocess,itisnecessarytoputupcontrolexperimentsasfaraspossible,whilethespecificfactorsunderconsiderationarenotrestricted.要记住，当通过实验来对这一过程的某些方面进行说明时，要尽可能进行对照实验，而所考虑的特殊因素并不受到限制。controlexperiment对照实验4.Inthesimplephotosyntheticexperiments,thepresenceofstarchintheleavesistakenasthecriterionthatcarbonassimilationhastakenplace,anditisthemethodthatshouldbedemonstratedthepresenceofstarchatfirst.在简易的光合作用实验中，叶片中淀粉的存在被看做是发生碳同化作用的判断标准，所以首先需要的是证明淀粉存在的方法。takeas把……看做是……；takeplace发生NOTES

5....whileacorrespondingplantisputbackintothedark,anotherwayisavailable,thatisaleafcanbecoveredwithamaskofblackpaperinwhichadesigncanbecutasastencilsothatlightcanreachthatpartoftheleaf.或者用另一种办法，可以把一片叶子用一张黑纸盖起来，在纸上剪出一个图案作为模板，使光能照射到那部分叶片。NOTESReadForMainIdeasChoosethebestanswerstocompleteeachsentence.1.Inmostplants,photosynthesisisindicatedby_____________.a.thechangeoftheleaves’colorb.theappearanceofstarchintheleaf-cellsc.thefruitsd.theseeds2.Thesynthesisofcarbohydratedependsonthepresenceof_____________.a.airandwaterb.lightandthegreensubstancechlorophyllc.light,thegreensubstancechlorophyll,carbondioxideandwaterd.carbondioxideandwaterReadForDetailsCompletethesentenceswiththefollowingwordsorphrases.Changewordformsifnecessary.alcoholphotosynthesisexposetodiprestrictDemonstrateillustratedissolveindicatetranslocate1.Driversmustkeepfrom（alcohol）

forsafedriving.2.（Dissolve）thesugarinthecoffeebystirringit.3.Youmustn’t（exposed）

medicinekept（to）

directsunshine,oritwillgobad.4.HowcanI（demonstrate）toyouthatmystoryistrue?5.Thearmy（translocated）thevictimstohigherplacestokeepawayfromtheflood.6.Whyshouldwe（restrict）theexercisestoonlytwokeywordspersentence?7.（Dip）

eachappleinthejamuntilthicklycoated.8.Youhavenowayto（indicate）

whetherthismethodiseffective.9.Through（photosynthesis）

plantsusethepowerofsunlighttoconvertwaterandcarbondioxideintosugar.10.Shedecidestousepicturesto（illustrate）

herpointofview.ReadForDetailsCompletethefollowingsentenceswithwordsfromReadingOne.1.Thesynthesisofcarbohydrateoccursinallgreenplantsinsunlight.2.Plantswithfairlylargeandthinleavesareveryconvenienttodotheexperiment.3.Thepresenceofstarchintheleavesistakenasthecriterionthatcarbonassimilationhastakenplace.4.Takealeaffromtheplantanddipintheboilingwatertokillit.5.Duringtheexperiments,severalplantsareputincompletedarknessfor24hours.6.Starchwillbeabsent,becauseithasbeentranslocatedfromtheleafduringthedarkperiod.ReadForDetailsWorkwithapartner.Readeachsentence.WriteT(true)orF(false).Thenshareyouranswerswiththeclass.1.Inallplantsthecompletionofthisprocessisindicatedbytheappearanceofstarchintheleaf-cells.F2.Someotherfactorscanprobablyaffecttherateofsynthesisbutdonotactuallycontrolit.T3.Plantswithfairlylargeandthinleavesareveryconvenienttodosimpleexperiments.T4.Starchwilltranslocatefromtheleafduringthetwenty-fourhoursdarkperiod.T5.Inthisexperiment,theleafwillnotchangethecolorwhetherthereisamaskcoveredonit.F6.Itisnecessarytoputupcontrolexperimentsasfaraspossible,whilethespecificfactorsunderconsiderationarenotrestricted.T7.Duringtheexperiment,puttheleafintothe80%warmethylalcohol.F8.Thelaststepoftheexperimentisputtingtheleavesintothediluteiodine.T9.Ifaportionoftheleafisexamined,thestarchgrainscanbeseenunderthemicroscope.T10.Afterexposuretolight,theexperimentalleafistestedforstarch.TExpressOpinionsHowtocarryoutasimpleexperimenttodemonstratehowdoesphotosynthesiswork?Pleasetellthesteps.Step1.Coveraleafwithamaskofblackpaper.Step2.Exposetheplanttothesunlightfortwoorthreehours.Step3.Diptheleafinwarm90%ethylalcohol.Step4.Washtheleafinwater.Step5.Dropafewdropsofdiluteiodineontheleaf.Step6.Thepartcoveredbythepaperwillappearcolorless;therestpartwillbeblackbecauseofthepresenceofstarch.Part4Task-drivenpracticeTask1Listentothefourconversations,andchoosethebestanswertoeachofthequestionsyouhear.1.A.Carrot.B.Icecream.C.Vitamin.2.A.One.B.Two.C.Three.3.A.Onthegrand.B.Onaladder.C.Inthewater.4.A.From7a.m.to9a.m.B.From6p.m.to9p.m.C.From7p.m.to9p.m.Task2Listentotheshortpassageandfillintheblankswithwhatyouhear.Today,theeconomicexistenceofmany(1)familyfarmsisbeingthreatenedbythemodernglobalagriculturaleconomy.Tooffsetthelossof(2)traditionalfarmincome,manyfarmsare(3)takingadvantageoftheiruniquenostalgic,ruralandoutdoorappealbydevelopingentertainment(4)attractionsasadditionalsourcesofincome,typicallyreferredtoas“agritainment”.Theseoptions(5)rangefromsuchstrategiesaspickyour-own,pettingzoos,cornmazes,andfarmstoresandrestaurants.OneofthemostsuccessfulindependententertainmentdestinationsintheUnitedStates,Knott’sBerryFarm,startedasatraditionalpick-your-ownberryfarm.Part4Task-drivenpracticeTask3ListentothedialogueandmarkthestatementswithT(true)orF(false).1.Peoplecometopickapplesbythemselvesandtakehomeforfun.T2.GreenFoodreferstotheplantsgrownwithoutusinganychemicals,fertilizers,andpesticides.T3.Farmersusepesticidestokillpests.F4.Jack’sfatheraskedhimtoknockdownthesmallapplesontheground.F5.Farmerscanmakesmallapplesintoapple-pie.FPart4Task-drivenpracticeTask4Listentothepassageandmatchthecorrectagritainmenttouristattractiontoeachdescription.1.ItisconsideredoneofNorthAmerican’smostsuccessfulHalloweenagritainmentattractions.(Vala’sPumpkinPatch)2.Itwasestablishedin1813,whichistheresultof6generationsoffamilydedication.(WestviewOrchards&CiderMill)3.Onceitwassaidtohavethelargestquinceorchardintheworld.(Brown’sBerryPatch)4.Itisapopulardestinationforschoolfieldtripsandfamiliesforitshayridestoitswidevarietyofu-pick-itproducefields.（Johnson’sCornerFarm）Part4Task-drivenpractice

Knott’sBerryFarmisathemeparkinCalifornia,ownedbyCedarFairEntertainmentCompany.Itisalsoalineofjams,jellies,preserves,andotherspecialfood.Knott’sisthemostvisitedparkintheCedarFairchainwith3.654millionvisitorsin2011.NOTEPart5ReadingtwoUSFacesWorstDroughtin56YearsTheUnitedStatesissufferingitsworstdroughtinalmostsixtyyears.Moderatetoextremedryconditionsspreadto50%ofthecountryinJune.ThatwasthemostsinceDecemberof1956.TheNationalClimaticDataCenteralsosayshightemperaturesinJunebecamethewarmesttwelve-monthperiodonrecord.Recordkeepingbeganin1895.

ThedroughtmapshowedthatconditionsinJuneimprovedintheSoutheastthanMay.ButtheystrengthenfromtheMidwesttotheGreatPlains（大平原）andmuchoftheWest.PredictionsthroughtheendofOctobersuggestthat,thedroughtislikelytoimproveinareasoftheSouthwestandSoutheast.Butthedroughtisexpectedtocontinueorstrengtheninlargepartsofthecountry.Mostoftheaffectedstatesareinthesouthernhalfofthecountry.Butofficialssaidfarmlandsinthenortharenowdryingupaswell.Part5ReadingtwoLastweek,AgricultureSecretary（农业部长）TomVilsackmetwithPresidentObama.Mr.Vilsacksaysthedroughthasseverelyaffectedcornandsoybeancrops.TheUnitedStatesistheworld’sleadingproducerofcornandsoybeans.Mr.Vilsacksaidtheoveralleffectofthedroughtishardtopredict.Someareasaregettingrain,anddrought-resistantseedshavehelpedcropsgrowwellinsomeareas.PresidentObamahascuttheinterestrateondisasterloans（灾害贷款）forfarmers,andmadeiteasierforaffectedareastoreceivegovernmentfinancialassistance.Atthesametime,farmersarewaitingtoseewhatCongress（国会）doeswiththefarmbill,amajorpieceoflegislationrenewedeveryfiveyears.TheSenate（参议院）haspassedaversionthatwouldenddirectpaymentstofarmersbuthelppayforcropinsurance.Theplanwouldsavemoney.ButtheHouseofRepresentative（众议院）haspasseddifferentlegislation,andCongressneedstoreachacompromise.ThecurrentfarmbillendsattheendofSeptember.Part6WritingWorkinpairs.FindthesupportingdetailsforthefollowingideasfromReadingTwo.ideasdetailsThedroughtisquiteseriousModeratetoextremedryconditionsspreadto50%ofthecountryinJune.ThatwasthemostsinceDecemberof1956.ThecontentofthedroughtmapConditionsinJuneimprovedintheSoutheastthanMay.ButtheyintensifiedfromtheMidwesttotheGreatPlainsandmuchoftheWest.TomVilsack’swordsaboutthedroughtThedroughthasseverelyaffectedcornandsoybeancrops.Theoveralleffectofthedroughtishardtopredict.PresidentObama’spolicyagainstthedroughtcuttheinterestrateondisasterloansforfarmers,andmadeiteasierforaffectedareastoreceivegovernmentfinancialassistance.Part7DoItYourself(D.I.Y.)Thefollowingpicturesareaboutthesimplephotosyntheticexperiment.Puttheminthecorrectorder,andthendescribehowtooperatethisexperiment.Part7DoItYourself(D.I.Y.)Thecorrectordershouldbe:5—2—3—1—6—4Step1.Coveraleafwithamaskofblackpaper.Step2.Exposetheplanttothesunlightfortwoorthreehours.Step3.Diptheleafinwarm90%ethylalcohol.Step4.Washtheleafinwater.Step5.Dropafewdropsofdiluteiodineontheleaf.Step6.Thepartcoveredbythepaperwillappearcolorless;therestpartwillbeblackbecauseofthepresenceofstarch.Afterlearningthisunit,youarerequiredtofinishthetestinsupplementarymaterial.Part8AchievementTestUnit2CanWeLiveWithoutSoil?I.FocusonthetopicII.VocabularystudyIIII.ReadingoneIV.Task-drivenpracticeV.Readingtwo

VI.

WritingCanWeLiveWithoutSoil?IVII.DoItYourself(D.I.Y.)Part1Focusonthetopic◆Searchthedefinitionofsoil.◆Discussabouttheimportantfunctionsofsoil.◆Listthewaystoprotectsoil.◆Discussthepossiblereasonsforsoilloss.Part2Vocabularystudy1.Readthesentences.Thencirclethedefinitionoftheboldfacedwords.Theglassbottlehasafewcracks,butitisstillusable.Acrackis__________________.a.ahurtb.anarrowopening(2)Thehotmetalcontractedasitcooled.Whensomethingcontracts,itbecomes__________________.a.largerb.smallerorshorter(3)HisbusinesshasexpandedfromChengdutotheentirecountry.Whensomethingexpandsorisexpanded,itbecomes__________________.a.largerb.smallerorshorterPart2Vocabularystudy(4)Fertilizersarewidelyusedintheworldtoenhancethegrowthofplants.Fertilizeris__________________.a.somethingusedtomakesoilmorefruitfulb.measuredbysoiltest(5)Humusisthedarkorganicmatterthatformsinthesoilwhenplantandanimalmatterrots.Whenthehumushasbeenformed,plantscangrow_____________init.a.wellb.badly(6)Yourshouldersneedtoremainlevelandshouldn’tmovefromsidetosidewitheachstep.Whensomethingislevel,itmeans___________.aspecificheightb.flat,notgoingupordownPart2Vocabularystudy(7)JulieandMikeaged17and18respectively.Thissentencemeans:__________________.a.Juliewas17andMikewas18b.JulieandMikewere17and18.(8)Theriverwaspollutedwiththewastefromthefactory.Wastemeans_______________.a.throwingawayb.anythingunusedandrejectedasworthlessorunwanted(9)Ifthetemperaturedropsbelow0℃,waterfreezes.Whenwaterfreezes,itbecomes__________________.a.softb.hardPart2Vocabularystudy(10)Wearenowingreatdemandofmaterialssuchascopperandiron.Materialrefersto_______________.a.thingsneededfordoingormakingsomethingb.differentpurposesPart2Vocabularystudy2.Matchthewordsintheleftcolumnwiththeirdefinitionsintherightcolumn.(1)Humus e a.材料，原料(2)waste b b.废品，废物(3)expand i c.（使）冻结，（使）结冰(4)contract g d.变得平坦；拉平(5)freeze c e.腐殖质；腐殖土(6)Material a f.肥料(7)fertilizer f g.收缩(8)level d h.分别地，各自地(9)crack j i.扩张；使膨胀(10)respectively h j.裂缝Part3ReadingoneSoilItistruethatalmostallofourfoodcomesfromthesoil.Someofusmaychoosemeat,ofcourse;butanimalsliveonplants.Iftherewerenoplants,wewouldhavenoanimalsandevennomeat.Sothesoilisnecessaryforlife.Thesurfaceofthesoilisusuallycoveredwithgrassorotherplants.Theremaybedeadleavesordeadplantsonthegrass.Plantsgrowinsoilwhichhasadarkcolorandthisdarksoiliscalledhumus（腐殖质；腐殖土）.Humuscontainsthingstakenfromdeadplants[1]andwastematterfromanimals.Thisgivesthesoilitscolor.Thesoilunderthehumusisnotdark.Thislightersoilisratherlikesand.Itismadeofbitofrock.Therocks,likeothermaterials,expandwithheatandcontractwithcold[2].Theyexpandandcontractonhotsummerdaysandcoldwinterdaysrespectively,whicheasilymakerocksbroken[3].Sometimeswatermayrunintoacrackinarock,anditfreezesonaverycoldday.Itexpandswhenthewaterfreezes.Part3Readingone(Itisastrangefact).Theicebecomesbiggerthanthewaterandbreakstherock,too.Sometimestherootsoftreesgrowintothecracksinrocks,andexpandlikeicedoesastheygrow,whichcanmaketherocksintopieces.Thebitsofrocklieontheground,orunderit,andtheyformakindofverypoorsoil.Deadplantsandwastematerialfromanimalsmakeitbetter,andslowlychangeitintohumus;however,thistakesalongtime.Whenthehumushasbeenformed,plantscangrowwellinit.Allsoilneedsfood.Withoutfood,theplantswillbeweak.Animalwasteisthebestfoodforthesoil,butchemicalfertilizersarestillveryuseful.Thesamecropoughtnottobegrowninthesameplaceeveryyear.Itisbettertohaveadifferentcrop[4].Achangeofcropandtheuseofagoodfertilizerwillkeepthelandingoodcondition.Part3ReadingoneWhenthesoilisdry,thewindblowsitaway.Someofthehumusislost;andifthiscontinues,thelandwillsoonlooklikeadesert.Farmersoughttopreventthis.Theycangrowtreesneartheirfields[5].Thesewillstoptheforceofthewind,andthenitcannotblowthehumusaway.Sometimesafterheavyrain,thewatercarriesthehumusdowntoariver.Thisoftenhappenswhenthefieldisonthesideofahill.Thewaterrushesdownthehillandtherivercarriesthehumusawaytothesea.Thefarmerscannotmakeanymorehumusquickly,buttheycanpreventthisiftheymaketheirfieldslevel.Thefieldonthehillsidefunctionsasthestairsofabighouse,andthusthewaterwillnotrushdowntotheriver,andthehumuswillstayinitsplace.Ittakeshundredsofyearstomakehumus,andsoweoughttosaveeverybitofit[6].Weneedmoreandmorefood.About200babiesareborneveryminute.Ofcourse,somepeopledie;buteverydaythereare120,000morepeoplebornintheworld.Thereareabout4,000millionpeopleintheworldnow.Attheendofthecenturytherewillbeabout8,000million.Wherewilltheother4,000milliongrowtheirfood?(574words)

1.Humuscontainsthingstakenfromdeadplants...腐殖土含有枯死植物的养料……taken在这里是过去分词表被动。2.Therocks,likeothermaterials,expandwithheatandcontractwithcold.岩石也同其他物质一样，热胀冷缩。这里like不是动词“喜欢”，而是介词“像”；likeothermaterials是插入语，插入语通常与句中其他部分没有直接的语法联系，删除后句子结构仍然完整。3.Theyexpandandcontractonhotsummerdaysandcoldwinterdaysrespectively,whicheasilymakerocksbroken.在炎热的夏季，岩石膨胀；在寒冷的冬季，岩石收缩。这样岩石便常常分崩离析。broken在这里不是形容词，而是过去分词。类似的词还有closed,frightened等，阅读时要看上下文来决定其词类及意义。NOTES

4.Itisbettertohaveadifferentcrop.最好进行轮作。“itisbettertodosomething”句型中，真正的主语是后面的不定式，表示“做什么……更好”的意思。通常的翻译中将itisbetter译成“最好”。5.Theycangrowtreesneartheirfields.他们可以在农田附近植树挡风。这句中的grow是及物动词，“种植”的意思，又如：growrice（种水稻），growwheat（种小麦）等。但grow又可做不及物动词，“生长”的意思，如：Thewheatinthisfieldisgrowingwell.（这块地里的小麦长势很好。）6.Ittakeshundredsofyearstomakehumus,andsoweoughttosaveeverybitofit.腐殖土的形成需要几百年的时间，所以应当避免任何损失。“Ittakes(sb.)timetodosomething”这是典型的时间花费句型。NOTESReadForMainIdeasChoosethebestanswerstocompleteeachsentence.1.Accordingtothepassage,thehumus______________________.a.isratherlikesandb.hasalightcolorc.takeshundredsofyearstomaked.ismeaninglessforplants2._____________willkeepthelandingoodcondition.a.Animalwasteb.Agoodfertilizerc.Achangeofcropd.AlloftheaboveReadForDetailsCompletethesentenceswiththefollowingwordsorphrases.Changewordformsifnecessary.materialwastefreezelevelhumusfertilizerrespectivelyexpandcrackcontract1.Theirdaughters,JoanandSophia,werethreeandsix（respectively）

.2.Itisa（waste）

oftimeandmoneytodevelopsuchanexpensivesystem.3.Theelectricitysupply（expanded）

by15%thisSeptember.4.Wespenthourscollectingallrelated（material）.5.Chemical（fertilizer）willkeepthesoilingoodcondition.

6.Researchesshowthatanoveruseofsaltandmeatcan（contracts）muscles.7.Weneedamechanicaldiggerto（level）theground.8.（Humus）isthepartofsoilwhichconsistsofdeadplants.9.Thereisa（crack）inthewall.10.Youcan（freeze）

thesoupnowincaseitgoesbad.ReadForDetailsCompletethesentenceswithwordsfromtheReadingOne.1.Thetopofthegroundisusuallycoveredwith（grassorotherplants.）.2.Thislightersoilisratherlikesand;itismadeof（bitofrock）

.3.Allsoilneeds（food）

.4.Ittakes（hundredsofyears）tomakehumus,andsoweoughttosaveeverybitofit.5.Theicetakesmorespacethan（thewater）

andthismayalsobreaktherocktoo.6.Thebitsofrocklie（ontheground）

,orunderit,andtheyformakindofverypoorsoil.ReadForDetailsWorkwithapartner.Readeachsentence.WriteT(true)orF(false).Thenshareyouranswerswiththeclass.1.Afterrain,thewatercarriesthehumusdowntoariver.F2.Thesamecropoughttobegrowninthesameplaceeveryyear.F3.Whenthehumushasbeenformed,plantscangrowwellinit.T4.Whenwaterfreezes,itexpands.T5.Thesoilunderthehumusisdark.F6.Thefarmerscanmakehumusveryquickly.F7.About100babiesareborneveryminute.F8.Deadplantsandwastematerialfromanimalsmakethesoilbetter.T9.Chemicalfertilizeristhebestfoodforthesoil.F10.Almostallofourfoodcomesfromthesoil.TExpressOpinionsGivebriefansw