A(13)1.Attentionmustbepaidtotheworkingtemperatureofthemachine.应当注意机器的工作温度。2.Anunderstandingofessentialcharacterofscientificinvestigationisbestacquiredfromthestudyofarepresentativeparticularscience.要了解科学研究最本质的特点,最好是对特定的典型学科进行研究。3.Asweknow,allmattersconsistofmolecules,andmoleculesofatoms.众所周知,一切物质由分子组成,而分子由原子组成。4.Allofthisprovesthatwemusthaveaprofoundstudyofpropertiesofproteins.所有这一切证明,我们必须深入地研究蛋白质特性。5.Anewkindofcomputer–small,cheap,fine—isattractingincreasingattention.一种新型的计算机越来越引起人们的注意——这种计算机体积小巧,价格低廉,性能优越。6.Acomputersystemconsistsofacomputerandsomeperipherals.计算机系统是由计算机和一些外部设备构成的。7.Adversetoiron,mercuryisinaliquidstateatordinarytemperature.水银与铁不同,在常温下是液态。8.ACcanbechangedintoDCwithgreatease.交流电可以极其容易地被转变成直流电。9.Animals,althoughtheyneedsomeinorganicfood,cannotliveonitalone.尽管动物需要无机物的营养,但是却不能单独以此维持生命。10.Anotherimportantfactortobetakenintoconsiderationisthatcurrentstrengthisequalatcertainpointinaseriescircuit.需要考虑在内的另一个重要因素是电流强度同串联电路中某些点的强度相同。11.AminimumelectricpowersystemisshowninFig.1,acombinationofanenergysource,aprimemover,agenerator,andaload.最小的电力系统如图1所示,它由能源、原动机、发电机和负载构成。12.ApartfromtheinternationalagenciescontrolledbytheU.N.,manyscientificandtechnologicalorganizations,bothgovernmentalandprivatelyowned,arepoolingtheirresourcesandincorporatingthemselvesintosupra-nationalbodies;agoodexampleistheOrganizationforEconomicCooperationandDevelopment,withover20member-countriesthroughouttheworld.除去联合国直属的国际机构之外,许多科技组织不论是政府的还是私营的,都在将它们的资源汇集起来并将自己合并成超国家的组织。由世界上20多个国家参加的经济合作与发展组织就是一个范例。13.Aluminumremainedunknownuntilthenineteenthcentury,becausenowhereinnatureisitfoundfree,owingtoitsalwaysbeingcombinedwithotherelements,mostcommonlywithoxygen,forwhichithasstrongaffinity.铝总是和其他元素结合在一起,最普遍的是和氧结合在一起,因为铝对氧有很强的亲和力。由于这个原因,在自然界中任何地方都找不到游离状态的铝;所以一直到十九世纪人们才知道有铝。B(4)14.Butforfriction,thedrivingwheelwouldnotrunthebelt,neitherwouldthebeltrunthewheeltobedriven.要是没有摩擦力,主动轮就不能带动皮带,皮带也就不能带动被动轮。15.Beingcooledintheair,thiskindofsteelbecomesharderandharder.在空气中冷却之后,这种钢就变得越来越硬。16.Bothofthesubstancesarenotsolubleinwater.这两种物质都不溶于水。17.Beinglargeorsmallallmagnetsbehavethesame.所有磁铁,无论大小,其性质都一样。C(3)18.Coolslowlytominimizecracking.要慢慢冷却,以最大限度的减少开裂。19.Computingmachinesareessentiallymachinesforrecordingnumbers,operatingwithnumbers,andgivingtheresultinnumericalform.计算机本质上是一种记录数字、运算数字并给出数字结果的机器。20.Copperhaslessresistancethanaluminumforthesamesizewire,butaluminum,beingmuchlighterinweight,haslessresistanceperunitofweight.对于同样粗细的电线来说,铜比铝的电阻小,但由于铝的重量很轻,所以它单位重量的电阻较小。D(5)21.Dependinguponcertainconditions,theremayormaynotbefreeelectronsinsemiconductors.半导体是否存在着自由电子,这取决于某些条件。22.Don`tletthestressesinsidethematerialexceedtheelasticlimit,orelsepermanentdeformationwillresult.不要使材料的应力超过弹性极限,否则会产生永久变形。23.Ductilityofametalisusuallymuchlesswhenhotthanwhencold.热状态的金属韧性一般要比冷状态的金属低得多。24.Designisaseriesofoperationsinvolvedintakingaproductfromaconceptualstagetoaformthatmeetsbothcompanygoalsandcustomerexpectations.设计是一系列的操作,包含该产品从构思阶段到同时满足公司目标和客户期望的结构样式。25.Dimensioningisacomplicatedworkandlongexperiencesarerequiredforthemasteringofit.进行尺寸标注是一项复杂的工作,需要长期经验才能完成。E(2)26.Eventhedissolutioninwatercannotenablecommonsalttochangeitschemicalproperties.即使我们将普通食盐溶于水,也不能改变其化学性质。27.Earthquakesseemlesseasytobecontrolledbymanthanweather.人类要控制地震似乎比控制天气更难。F(3)28.Fig1incorporatesmanyofthefactorswhichmustbeconsideredindevelopingasatisfactorysystem.图1所示的许多因素,在研制性能良好的系统时必须予以考虑。29.FaradaydiscoveredtheLawofElectromagneticInductionafteryearsoftrial,error,andtrialagain.经过几年的试验、失败、再实验,法拉第终于发现了电磁感应定律。30.Forreasonsthealternatingcurrentismorewidelyusedthanthedirectcurrent.由于种种原因,交流电比直流电用得更加广泛。G(6)31.Gasesdifferfromsolidsinthattheformerhavegreatercompressibilitythanthelater.气体和固体的区别在于前者比后者有更大的压缩性。32.Gasolineisappreciablyvolatile.汽油具有很强的挥发性。33.Goldissimilarincolortobrass.金子的颜色和黄铜相似。34.Goingthroughtheprocessofheattreatment,metalsbecomemuchstrongerandmoredurable.金属经过热处理后,强度更大,更加耐用。35.Giventheweightandthespecificgravityofabody,wecancalculateitsvolume.已知物体的重量和比重,就可求出其体积。36.Greateffortswillbemadetoachieveadvancementandindependentinnovationoftechnology,whichwillleadtoimprovedsafetyandcost-efficiencyofnuclearpowerreactorsandcompetitivenessofnuclearpower.我们将更努力实现先进的技术和技术的自我更新,这将提高核反应堆的安全和成本效益及核电的综合性能。H(1)37.Hydroelectricstationsofferquiteanumberofadvantagesovertheirthermalandnuclearcounterparts.与火电厂和核电厂相比,水电厂有很大的优势。I(20)38.Inthiscasethetemperatureinthefurnaceisup.在这种情况下,炉温就升高。39.Ifwehadknownthepropertiesofthematerial,weshouldhavemadefulluseofit.要是当时了解这种材料的特性的话,我们就会充分利用它了。40.Ingeneral,allthemetalsaregoodconductors,withsilverthebestandcopperthesecond.一般来说,金属都是良导体,其中以银为最好,铜次之。41.Ifwewereignorantofthestructureoftheatom,itwouldbeimpossibleforustostudynuclearphysics.如果我们不知道原子的结构,就不可能研究核子物理学。42.Itisverymuchlikecommunicatingwithanaccuraterobotwhohasaverysmallvocabularyandtakeseverythingliterally.这就像和一丝不苟的机器人说话,机器人只有很少的词汇,而且你怎么说他就怎么做。43.Itstransmissionoverlongdistancecausessomelossofenergy.长距离输送会损耗一些能量。44.Ittakesabodypreciselyaslongtofallfromaheighthasitdoestorisethathigh.物体从高度h下落所需要的时间与它上升到同一高度所需的时间完全相同。45.Ingeneral,all