新概念第四冊(cè)+Lesson+67++Obtaining+Fresh+water+from+icebergs+講義

新概念第四冊(cè)lesson67講義ObtainingFreshwaterfromicebergsObtainingFreshwaterfromicebergs1

Theconceptofobtainingfreshwaterfromicebergsthataretowedtopopulatedareasandarid2regionsoftheworldwasoncetreatedasajokemoreappropriatetocartoonsthanreallife.Butnowitisbeingconsideredquiteseriouslybymanynations,especiallysincescientistshavewarnedthatthehumanracewilloutgrow3itsfreshwatersupplyfasterthanitrunsoutoffood.Glaciers4areapossiblesourceoffreshwaterthathasbeenoverlookeduntilrecently.Three-quartersoftheEarth’sfreshwatersupplyisstilltiedupinglacialice,areservoirofuntappedfreshwatersoimmensethatitcouldsustainalltheriversoftheworldfor1,000years.Floatingontheoceanseveryyearare7,659trillionmetrictonsoficeencasedin10000icebergsthatbreakawayfromthepolaricecaps,morethanninetypercentofthemfromAntarctica.Hugeglaciersthatstretchovertheshallowcontinental5shelfgivebirthtoicebergsthroughouttheyear.Icebergsarenotlikeseaice,whichisformedwhentheseaitselffreezes,rather,theyareformedentirely6onland,breakingoffwhenglaciersspreadoverthesea.Astheydriftawayfromthepolarregion,icebergssometimesmovemysteriouslyinadirectionoppositetothewind,pulledbysubsurfacecurrents.Becausetheymeltmoreslowlythansmallerpiecesofice,icebergshavebeenknowntodriftasfarnorthas35degreessouthoftheequatorintheAtlanticOcean.Tocorralthemandsteer7themtopartsoftheworldwheretheyareneededwouldnotbetoodifficult.Thedifficultyarisesinothertechnicalmatters,suchasthepreventionofrapidmeltinginwarmerclimatesandthefunneling8offreshwatertoshoreingreatvolume.Buteveniftheicebergslosthalfoftheirvolumeintowing,thewatertheycouldprovidewouldbefarcheaperthanthatproducedbydesalinization,orremovingsaltfromwater.從冰山中獲取淡水把冰山拖到世界上人口稠密的地區(qū)和干旱地帶，再從中獲取淡水，這個(gè)想法曾一度被認(rèn)為是一個(gè)笑話，更適合于卡通畫，而非現(xiàn)實(shí)生活。然而現(xiàn)在，許多國(guó)家正相當(dāng)認(rèn)真地考慮這件事情，特別是在科學(xué)家們發(fā)出警告之后。科學(xué)家們認(rèn)為人類將在耗盡糧食之前首先耗盡淡水資源。冰川是一個(gè)直到最近以前一直被忽視的可能的淡水源。全球四分之三的淡水還鎖在冰川的冰塊中。冰川就是一個(gè)蓄水池，其中未開發(fā)的淡水量是如此巨大，足夠支持全世界的江河1000年。每年有7，659萬億公噸冰漂流在海洋中。它們包含在10，000座從極地冰帽中斷裂出來的冰山中。這些冰山的90%以上來自南極。一年四季里，覆蓋在淺層大陸架上的巨大冰川生成了眾多冰山。冰山和海水的冰不同，后者是海水自身結(jié)冰形成的，而冰山則完全是在陸地上形成的。當(dāng)冰川伸展到海水中時(shí)，冰山就斷裂下來。當(dāng)漂離極地地區(qū)時(shí)，冰山有時(shí)會(huì)在底層洋流的推動(dòng)下頗為神秘地逆風(fēng)移動(dòng)。由于冰山比小塊的冰融化要慢，因此有的冰山在大西洋中向北飄到了赤道以南35°的地方。把冰山蓄攔起來并拖到世界上需要它們的地方將不會(huì)太困難。有困難的是其它的技術(shù)事宜。比如，如何防止冰山在較暖的氣候中迅速融化以及如何把大量的淡水收集到岸上去。但是，即便在拖的過程中冰山失去了一半體積，這樣做也遠(yuǎn)比從海水中脫鹽取得淡水便宜。點(diǎn)擊收聽單詞發(fā)音

1icebergs

n.冰山，流冰(iceberg的名詞復(fù)數(shù))參考例句：Thedriftoftheicebergsintheseaendangerstheships.海上冰山的漂流危及船只的安全。來自《簡(jiǎn)明英漢詞典》Theicebergstoweredabovethem.冰山高聳于他們上方。來自辭典例句2arid

adj.干旱的；(土地)貧瘠的參考例句：Thesetreeswillshieldoffaridwindsandprotectthefields.這些樹能擋住旱風(fēng),保護(hù)農(nóng)田。Thereareseriousproblemsoflanddegradationinsomearidzones.在一些干旱地帶存在嚴(yán)重的土地退化問題。3outgrow

vt.長(zhǎng)大得使…不再適用；成長(zhǎng)得不再要參考例句：Thelittlegirlwilloutgrowherfearofpetanimals.小女孩慢慢長(zhǎng)大后就不會(huì)在怕寵物了。Childrenwhowalkintheirsleepusuallyoutgrowthehabit.夢(mèng)游的孩子通常在長(zhǎng)大后這個(gè)習(xí)慣自然消失。4glaciers

冰河，冰川(glacier的名詞復(fù)數(shù))參考例句：Glaciersgougedoutvalleysfromthehills.冰川把丘陵地帶沖出一條條山谷。Ithasiceandsnowglaciers,rainforestsandbeautifulmountains.既有冰川，又有雨林和秀麗的山峰。來自英語晨讀30分（高一）5continental

adj.大陸的，大陸性的，歐洲大陸的參考例句：Acontinentalclimateisdifferentfromaninsularone.大陸性氣候不同于島嶼氣候。Themostancientpartsofthecontinentalcrustare4000millionyearsold.大陸地殼最古老的部分有40億年歷史。6entirely

ad.全部地，完整地；完全地，徹底地參考例句：Thefirewasentirelycausedbytheirneglectofduty.那場(chǎng)火災(zāi)完全是由于他們失職而引起的。Hislifewasentirelygivenuptotheeducationalwork.他的一生統(tǒng)統(tǒng)獻(xiàn)給了教育工作。7steer

vt.駕駛，為…操舵；引導(dǎo)；vi.駕駛參考例句：Ifyoupushthecar,I'llsteerit.如果你來推車，我就來駕車。It'snousetryingtosteertheboyintoacourseofactionthatsuitsyou.想說服這孩子按你的方式行事是徒勞的。8funneling

[醫(yī)]成漏斗形：描述膀胱底及膀胱尿道交接區(qū)TheSourceofEnergeThesourceofEnergyAsummaryofthephysicalandchemicalnatureoflifemustbegin,notontheEarth,butintheSun;infact,attheSun’sverycenter.ItisherethatistobefoundthesourceoftheenergythattheSunconstantlypoursoutintospaceaslightandheat.ThisenergyislibratedatthecenteroftheSunasbillionsuponbillionsofnuclei1ofhydrogenatomscollidewitheachotherandfusetogethertoformnucleiofhelium,andindoingso,releasesomeoftheenergythatisstoredinthenucleiofatoms.TheoutputoflightandheatoftheSunrequiresthatsome600milliontonsofhydrogenbeconvertedintoheliumintheSuneverysecond.ThistheSunhasbeendoingforseveralthousandsofmillionsofyear.ThenuclearenergyisreleasedattheSun’scenterashigh-energygammaradiation,aformofelectromagneticradiationlikelightandradiowaves,onlyofverymuchshorterwavelength2.ThisgammaradiationisabsorbedbyatomsinsidetheSuntobereemittedatslightlylongerwavelengths3.Thisradiation,initsturnisabsorbedandreemitted.Astheenergyfiltersthroughthelayersofthesolarinterior,itpassesthroughtheX-raypartofthespectrum4eventuallybecominglight.Atthisstage,ithasreachedwhatwecallthesolarsurface,andcanescapeintospacewithoutbeingabsorbedfurtherbysolaratoms.AverysmallfractionoftheSun’slightandheatisemittedinsuchdirectionsthatafterpassingunhinderedthroughinterplanetaryspace,ithitstheEarth.能量的來源概說生命的物理和化學(xué)特性必須始于太陽--確切地說，是太陽的核心，而非地球。能量來自太陽的核心。在這里，太陽不停地以光和熱的形式向空間傾瀉出能量。數(shù)十億計(jì)的氫原子核在太陽的核心碰撞并且聚變生成氦。在此過程中一部分原本儲(chǔ)存于原子核中的能量被釋放出來。太陽所產(chǎn)生的光和熱需要每秒將六億噸氫轉(zhuǎn)化為氦。這樣的轉(zhuǎn)化在太陽中已經(jīng)持續(xù)幾十億年了。核能在太陽的核心被釋放為高能的伽馬射線。這是一種電磁射線，就象光波和無線電波一樣，只是波長(zhǎng)要短得多。這種伽瑪射線被太陽內(nèi)的原子所吸收，然后重新釋放為波長(zhǎng)稍長(zhǎng)一些的光波。這新的射線再次被吸收，而后釋放。在能量由太陽內(nèi)部一層層滲透出來的過程中，它經(jīng)過了光譜中X射線部分，最后變成了光。在此階段，能量到達(dá)我們所稱的太陽表層，并且離散到空間而不再被太陽原子所吸收。只有很小一部分太陽的光和熱由此方向釋放出來，并且未被阻擋，穿越星空，來到地球。

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1nuclei

n.核參考例句：Tofreeelectrons,somethinghastomakethemwhirlfastenoughtobreakawayfromtheirnuclei.為了釋放電子，必須使電子高速旋轉(zhuǎn)而足以擺脫原子核的束縛。Energyisreleasedbythefissionofatomicnuclei.能量是由原子核分裂釋放出來的。2wavelength

n.波長(zhǎng)參考例句：Theauthoritieswereunabletojamthiswavelength.當(dāng)局無法干擾這一波長(zhǎng)。RadioOnehasbroadcastonthiswavelengthforyears.廣播1臺(tái)已經(jīng)用這個(gè)波長(zhǎng)廣播多年了。3wavelengths

n.波長(zhǎng)(wavelength的名詞復(fù)數(shù))；具有相同的/不同的思路；合拍；不合拍參考例句：Ifindhimdifficulttotalkto—we'reoncompletelydifferentwavelengths.我沒法和他談話，因?yàn)槲覀儌z完全不對(duì)路。來自《簡(jiǎn)明英漢詞典》Sunlightconsistsofdifferentwavelengthsofradiation.陽光由幾種不同波長(zhǎng)的射線組成。來自辭典例句4spectrum

n.譜，光譜，頻譜；范圍，幅度，系列參考例句：Thisisakindofatomicspectrum.這是一種原子光譜。Wehaveknownmuchoftheconstitutionofthesolarspectrum.關(guān)于太陽光譜的構(gòu)成，我們已了解不少。Vision.VisionHumanvisionlikethatofotherprimates2hasevolvedinanarboreal3environment.Inthedense4complexworldofatropicalforest,itismoreimportanttoseewellthattodevelopanacutesenseofsmell.Inthecourseofevolutionmembersoftheprimate1linehaveacquiredlargeeyeswhilethesnouthasshrunktogivetheeyeanunimpededview.Ofmammalsonlyhumansandsomeprimatesenjoycolorvision.Theredflagisblacktothebull.Horsesliveinamonochromeworld.lightvisibletohumaneyeshoweveroccupiesonlyaverynarrowbandinthewholeelectromagneticspectrum5.Ultravioletraysareinvisibletohumansthoughantsandhoneybeesaresensitivetothem.Humansthoughantsandhoneybeesaresensitivetothem.Humanshavenodirectperceptionofinfrared6raysunliketherattlesnakewhichhasreceptorstuned7intowavelengths8longerthan0.7micron.Theworldwouldlookeerily9differentifhumaneyesweresensitivetoinfraredradiation.Theninsteadofthedarknessofnight,wewouldbeabletomoveeasilyinastrangeshadowlessworldwhereobjectsglowedwithvaryingdegreesofintensity10.Buthumaneyesexcelinotherways.Theyareinfactremarkably11discerningincolorgradation.Thecolorsensitivityofnormalhumanvisionisrarelysurpassedevenbysophisticatedtechnicaldevices.視覺人類的視覺，和其它靈長(zhǎng)目動(dòng)物的一樣，是在叢林環(huán)境中進(jìn)化出來的。在稠密、復(fù)雜的熱帶叢林里，好的視覺比靈敏的嗅覺更加重要。在進(jìn)化過程中，靈長(zhǎng)目動(dòng)物的眼睛變大，同時(shí)鼻子變小以使視野不受阻礙。在哺乳類動(dòng)物中，只有人和一些靈長(zhǎng)目動(dòng)物能夠分辨顏色。紅旗在公?？磥硎呛谏?，馬則生活在一個(gè)單色的世界里。然而，人眼可見的光在整個(gè)光譜中只占一個(gè)非常狹窄的頻段。人是看不到紫外線的，盡管螞蟻和蜜蜂可以感覺到。與響尾蛇不同，人也不能直接感受到紅外線。響尾蛇的感覺器可以感受波長(zhǎng)超過0.7微米的光線。如果人能感受到紅外線的話，這世界看上去將十分不同，而且恐怖。到那時(shí)，將與夜的黑暗相反，我們能輕易地在一個(gè)奇異的沒有陰影的世界里走動(dòng)。任何物體都強(qiáng)弱不等地閃著光。然而，人眼在其它方面有優(yōu)越之處。事實(shí)上，人眼對(duì)顏色梯度具有非凡的分辨能力。普通人類的視覺感受色彩的靈敏程度，甚至連精密的技術(shù)裝備都很難超越。點(diǎn)擊收聽單詞發(fā)音

1primate

n.靈長(zhǎng)類（目）動(dòng)物，首席主教；adj.首要的參考例句：14percentofprimatespeciesarehighlyendangered.14%的靈長(zhǎng)類物種處于高度瀕危狀態(tài)。ThewoollyspidermonkeyisthelargestprimateintheAmericas.絨毛蛛猴是美洲最大的靈長(zhǎng)類動(dòng)物。2primates

primate的復(fù)數(shù)參考例句：Primatesarealert,inquisitiveanimals.靈長(zhǎng)目動(dòng)物是機(jī)靈、好奇的動(dòng)物。Consciousnessorcerebrationhasbeensaidtohaveemergedintheevolutionofhigherprimates.據(jù)說意識(shí)或思考在較高級(jí)靈長(zhǎng)類的進(jìn)化中已出現(xiàn)。3arboreal

adj.樹棲的；樹的參考例句：Manwasevolvedfromanancestorthatwasprobablyarboreal.人大概是從住在樹上的祖先進(jìn)化而來的。KoalaisanarborealAustralianmarsupial.考拉是一種澳大利亞樹棲有袋動(dòng)物。4dense

a.密集的，稠密的，濃密的；密度大的參考例句：Thegeneralambushedhistroopsinthedensewoods.將軍把部隊(duì)埋伏在濃密的樹林里。Thepathwascompletelycoveredbythedensefoliage.小路被樹葉厚厚地蓋了一層。5spectrum

n.譜，光譜，頻譜；范圍，幅度，系列參考例句：Thisisakindofatomicspectrum.這是一種原子光譜。Wehaveknownmuchoftheconstitutionofthesolarspectrum.關(guān)于太陽光譜的構(gòu)成，我們已了解不少。6infrared

adj./n.紅外線(的)參考例句：Infrarediswidelyusedinindustryandmedicalscience.紅外線廣泛應(yīng)用于工業(yè)和醫(yī)學(xué)科學(xué)。Infraredradiationhaswavelengthslongerthanthoseofvisiblelight.紅外輻射的波長(zhǎng)比可見光的波長(zhǎng)長(zhǎng)。7tuned

adj.調(diào)諧的，已調(diào)諧的v.調(diào)音(tune的過去式和過去分詞)；調(diào)整；（給收音機(jī)、電視等）調(diào)諧；使協(xié)調(diào)參考例句：Theresortistunedintothetastesofyoungandoldalike.這個(gè)度假勝地適合各種口味，老少皆宜。Theinstrumentsshouldbetunedupbeforeeachperformance.每次演出開始前都應(yīng)將樂器調(diào)好音。來自《簡(jiǎn)明英漢詞典》8wavelengths

n.波長(zhǎng)(wavelength的名詞復(fù)數(shù))；具有相同的/不同的思路；合拍；不合拍參考例句：Ifindhimdifficulttotalkto—we'reoncompletelydifferentwavelengths.我沒法和他談話，因?yàn)槲覀儌z完全不對(duì)路。來自《簡(jiǎn)明英漢詞典》Sunlightconsistsofdifferentwavelengthsofradiation.陽光由幾種不同波長(zhǎng)的射線組成。來自辭典例句9eerily

adv.引起神秘感或害怕地參考例句：Itwasnearlymid-nightandeerilydarkallaroundher.夜深了，到處是一片黑黝黝的怪影。來自漢英文學(xué)-散文英譯Thevastvolcanicslopewaseerilyreminiscentofalunarlandscape.開闊的火山坡讓人心生怪異地聯(lián)想起月球的地貌。來自辭典例句10intensity

n.強(qiáng)烈，劇烈；強(qiáng)度；烈度參考例句：Ididn'trealizetheintensityofpeople'sfeelingsonthisissue.我沒有意識(shí)到這一問題能引起群情激奮。Thestrikeisgrowinginintensity.罷工日益加劇。11remarkably

ad.不同尋常地，相當(dāng)?shù)貐⒖祭洌篒thoughtshewasremarkablyrestrainedinthecircumstances.我認(rèn)為她在那種情況下非?？酥啤emadearemarkablyswiftrecovery.他康復(fù)得相當(dāng)快。FolkCultureAfolkcultureisasmallisolated1,cohesive2,conservative,nearlyself-sufficientgroupthatishomogeneousincustomandracewithastrongfamilyorclan3structureandhighlydevelopedrituals.Orderismaintainedthroughsanctionsbasedinthereligionorfamilyandinterpersonal.Relationshipsarestrong.Traditionisparamount4,andchangecomesinfrequentlyandslowly.Thereisrelatively5littledivisionoflabor6intospecialized7duties.Rather,eachpersonisexpectedtoperformagreatvarietyoftasks,thoughdutiesmaydifferbetweenthesexes.Mostgoodsarehandmadeandsubsistenceeconomyprevails.Individualismisweaklydevelopedinfolkculturesasaresocialclasses.UnalteredfolkculturesnolongerexistinindustrializedcountriessuchastheUnitedStatesandCanada.PerhapsthenearestmodernequivalentinAngloAmericaistheAmish,aGermanAmericanfarmingsect8thatlargelyrenounces9theproductsandlaborsavingdevicesof

theindustrialage.InAmishareas,horsedrawn10buggiesstillserveasalocaltransportationdeviceandthefaithfularenotpermittedtoownautomobiles11.TheAmish’scentralreligiousconceptofDemut

“humility”,clearlyreflectstheweaknessofindividualismandsocialclasssotypicaloffolkculturesandthereisacorrespondingstrengthofAmishgroupidentity.RarelydotheAmishmarryoutsidetheirsect.Thereligion,avarietyoftheMennonitefaith,providestheprincipalmechanism12formaintainingorder.Bycontrastapopularcultureisalargeheterogeneous13groupoftenhighlyindividualisticandapronouncedmanyspecializedprofessions.Secular14institutionsofcontrolsuchasthepoliceandarmytaketheplaceofreligionandfamilyinmaintainingorder,andamoney-basedeconomyprevails.Becauseofthesecontrasts,“popular”maybeviewedasclearlydifferentfrom“folk”.Thepopularisreplacingthefolkinindustrializedcountriesandinmanydevelopingnations.Folk-madeobjectsgivewaytotheirpopularequivalent,usuallybecausethepopularitemismorequicklyorcheaplyproduced,iseasierortimesavingtouseorleadsmoreprestigetotheowner.

民間文化民間文化是小型的、孤立的、緊密的、保守的、近乎自給自足的群體，具有同樣的習(xí)俗、同樣的人種和強(qiáng)有力的家庭或部族結(jié)構(gòu)以及高度發(fā)展的宗教儀式。秩序由宗教或家庭的約束來維持，成員間的關(guān)系非常緊密，傳統(tǒng)至高無上，很少有變動(dòng)且變動(dòng)緩慢。勞動(dòng)專業(yè)分工相對(duì)較少。每個(gè)人都要做各類活計(jì)，盡管男女兩性分工不同。絕大多數(shù)物品是手工制造的，經(jīng)濟(jì)一般為自給自足型。個(gè)人主義和社會(huì)階層在民間文化群體中的發(fā)展十分薄弱。在象美國(guó)和加拿大這樣的工業(yè)化國(guó)家里，一成不變的民間文化群體已不復(fù)存在了。在當(dāng)代美洲的英語區(qū)，與民間文化最相似的群體也許算是Amish。Amish是美國(guó)的德裔農(nóng)耕部落，他們基本上拒絕接受工業(yè)時(shí)代的大多數(shù)產(chǎn)品和節(jié)省勞力的設(shè)施。在Amish地區(qū)，輕便馬車仍是當(dāng)?shù)氐慕煌üぞ?，信徒們不允許擁有汽車。Amish宗教中的核心觀念Demut即謙卑典型地反映了在民間文化群中個(gè)人主義和階級(jí)的不發(fā)達(dá)。而與此同時(shí)，Amish對(duì)群體的認(rèn)同性卻十分強(qiáng)。Amish人很少和他們宗派以外的人通婚。其宗教，作為Mennonite信仰的一種，提供了維護(hù)秩序的主要機(jī)制。相反，大眾文化是包含不同種族的大群體，通常高度個(gè)性化而且不斷在變化。人際關(guān)系冷漠，勞動(dòng)分工明確，由此產(chǎn)生了許多專門的職業(yè)。世俗的控制機(jī)構(gòu)，比如警察和軍隊(duì)，取代了宗教和家庭來維持秩序，而且實(shí)行的是貨幣經(jīng)濟(jì)。由于存在著這些差異，"大眾的"與"民間的"可謂大相徑庭。在工業(yè)化國(guó)家以及許多發(fā)展中國(guó)家里，大眾文化正在取代民間文化。民間制造的物品正讓位于大眾化產(chǎn)品，這通常是因?yàn)榇蟊娀奈锲分圃炱饋砀?、更便宜，用起來更容易、更方便或者是能給其所有者帶來更多的威望。點(diǎn)擊收聽單詞發(fā)音

1isolated

adj.與世隔絕的參考例句：Hisbadbehaviourwasjustanisolatedincident.他的不良行為只是個(gè)別事件。Patientswiththediseaseshouldbeisolated.這種病的患者應(yīng)予以隔離。2cohesive

adj.有粘著力的；有結(jié)合力的；凝聚性的參考例句：Shesealedtheparcelwithcohesivetape.她用粘膠帶把包裹封起來。Theauthorskillfullyfusesthesefragmentsintoacohesivewhole.作者將這些片斷巧妙地結(jié)合成一個(gè)連貫的整體。3clan

n.氏族，部落，宗族，家族，宗派參考例句：Sheranksasmyjuniorintheclan.她的輩分比我小。TheChineseChristians,therefore,practicallyexcommunicatethemselvesfromtheirownclan.所以，中國(guó)的基督徒簡(jiǎn)直是被逐出了自己的家族了。4paramount

a.最重要的，最高權(quán)力的參考例句：MyparamountobjectistosavetheUnionanddestroyslavery.我的最高目標(biāo)是拯救美國(guó)，摧毀奴隸制度。Nitrogenisofparamountimportancetolifeonearth.氮對(duì)地球上的生命至關(guān)重要。5relatively

adv.比較...地，相對(duì)地參考例句：TherabbitisarelativelyrecentintroductioninAustralia.兔子是相對(duì)較新引入澳大利亞的物種。Theoperationwasrelativelypainless.手術(shù)相對(duì)來說不痛。6labor

n.勞動(dòng)，努力，工作，勞工；分娩；vi.勞動(dòng)，努力，苦干；vt.詳細(xì)分析；麻煩參考例句：Weareneverlateinsatisfyinghimforhislabor.我們從不延誤付給他勞動(dòng)報(bào)酬。Hewascomplet