?Natural gas, which is the lighter hydrocarbon fraction, and in particular methane, may range from a small quantity dissolved in the crude oil through a separate gaseous capping over an oil pool to a separate large accumulation not associated with a nearby oil pool. ?天然气是较轻的碳氢化合物，其主要成分是甲烷，可能数量很少而溶解在原油中，可能含量较多而在油层上面自成一气顶，也可能与附近的油层无关而单独地大量储积。（译成谓语部分）
?In larger amounts, ozone is unpleasant with a strong odour that irritates the eyes and lungs.?大量的臭氧带有一种不舒服的强烈气味，对眼睛及肺部有刺激作用。（译为并列谓语） ?Recent scientific innovations point to a future where tiny amounts of electricity will run superfast computers.?最近的科学创新表明，在未来，极少量的电能就足以运行超高速计算机。（译为宾语）
?We live in an age where voice, data, and video are just bits, ones and zeros. ?在我们的生活时代，数据、声音、视频都是比特，即1或0。（主句译成状语，where引导的定语从句译成主句）
?Prolonged fasting is an extremely effective – though not necessarily desirable – way to lose weight in a hurry. Much depends on the type of fast (which) you undertake.?尽管长期禁食不是快速减肥的合适方法，但它非常有效。减肥的效果在很大程度上取决于禁食的类型。(省译定语从句)
?The information is stored as a reference sample, which is often referred to as a template. ?将这些信息作为参考样本（常称作模板）储存起来。 （补充说明）
?The turbines drive the dynamos which generate the electricity.?汽轮机驱动发电机发电。（译为汉语的兼语句）?
?七、两种特殊结构定语从句的译法
?（一）介词+which定语从句的译法?介词+which定语从句多数作限制性定语从句，少数也可以作非限制性定语从句，这种定语从句的译法和上面所讲定语从句的译法基本一致。如： ?At the center of an atom there is a nucleus, around which electrons revolve.?原子的中心是原子核，电子绕原子核旋转。（译为并列分句）
?In many cases there is no ambiguity as to which substance is the solute and which is the solvent.
?至于哪种物质是溶质，哪种物质是溶剂，在许多情况下都是一清二楚的。(译为主语) ?There is a minimum size for the reactor at which the chain reaction will just work. ?为使链式反应刚好能够维持下去，反应堆要有一个最起码的尺寸。（译为目的状语从句） ?The rate of condensation is governed by the rate at which latent heat is carried away from the surface to cooler vapor.?冷凝速度由汽化潜热从该表面转入冷蒸汽的速度确定。（译为带―的‖定语）
?Any change in which no new substance is formed is a physical change. ?任何变化只要不生成新的物资，都是物理变化。（译为条件状语从句）
?With this arrangement each load has two or more circuits over which electricity is fed.?在这种配置下，每个负载有两个甚至更多的线路为其供电。（over which引导限制性定语从句，被译为汉语兼语结构的一部分）
?（二）名词（代词）+of+关系代词（主要是which）定语从句的译法?名词（代词）+of+关系代词的定语从句主要是作非限制性定语从句。这种定语从句相当于whose +名词的定语从句，这种定语从句大都译为一个并列分句（有时也可译作定语的―的‖字结构）。如果of 前为名词，which可以被译为它所代替的名词，也可译为―其……‖，并在分句中做主语。如：
?A force can be shown by a straight line, the length of which represents the magnitude of the force.?力用直线表示，直线的长度表示力的大小。?When a movement of free electrons is produced in one particular direction, this constitutes an electric current, the magnitude of which depends on the number of free electrons passing per second.?当这种自由电子按一定方向移动时，就形成了电流；电流的大小取决于每秒经过的自由电子数。?Molecules make up matter, the state of which can be changed.?分子组成物质，物质的形态是能改变的。?Some metals have special additional properties, two of which are the ability to conduct currents and to be magnetized.?有些金属还具有另外的特性，其中两种是有导电的能力和被磁化的能力。?Perhaps light is some sort of electric wave, the nature of which we do not yet understand.?也许，光是某种电波，其性质我们尚不清楚。 第三节 状语从句的翻译
?（一）直译?这里的直译就是说把时间状语从句译成汉语的时间状语，并译出连接词本身的意义。要注意的是英语的时间状语从句既可以置于主句之前，也可置于主句之后，有时也可以放在句子的中间。但汉译时，为了使译文符合汉语的习惯，不论原句子中时间状语从句是在句首还是句尾，或是在句子中间，原则上应译在句首。如：
?Certain sweat glands emit a distinctive odour when an animal is frightened.
?动物受惊吓时，某些汗腺会放出独特的气味。?Whenever a wave moves out from a source in uniform medium, it travels in straight lines.?每当波从均匀介质中的波源移出时，它都呈直线传播。
?The leaves separate before the metallic board is touched. ?在接触金属板以前簧片分开。
?As soon as such a cap was formed, there was instant and typical response on the part of the organ.?根冠一形成，器官部分就立即作出典型的反应。
?The adjustment must be repeated each time the vessel is changed. ?每当更换容器时都要重新调整。
?The machine starts the moment (that) the button is pressed. ?一按电钮，机器就开动了。
?Start the measurements after the effect of body temperature is removed.
?待物体温度影响消除之后再开始测量。?Since numerical control was adopted in machine tools, the productivity has been raised greatly.?自从机床采用数控以来，生产率大大提高了。?
?二）when引导的状语从句的特殊译法?1．when引导的时间状语从句除了译为―当……时‖，还可以译为―在……之后，如：
?Some people develop skin rashes when they take sulfas. ?有些人服用磺胺药物后会出现皮疹。?When our high level language program is fed into the machine, the compiler translates it into machine code so that it can be followed by the computer.
?高级语言程序输入计算机之后，编译程序就把它译成机器代码，以便计算机执行。
?2．when引导的状语从句除了表示时间外，还可以表示条件，可译为―若‖、―如果‖、―一旦‖等。如：?When a foundation is laid in poor soil, it is necessary to excavate to a greater depth than normal to reach a solid base.?若将基础建在地基土层较差地方，其基坑的深度必须大于常规深度，以使基础落于较坚实的地基上。
?Insurance companies are obliged to recover the cost of everything insured when it is lost or damaged during the valid period of insurance.
?一切经过保险的东西，如在有效保险期内丢失或受损，保险公司要赔偿其成本。 ?When it has all these details, the central computer sends back to the driver via the buried electronic unit the best possible route.?中心计算机一旦（如果）获得所有这些详情，就能通过埋在道路下的电子装置将最佳路线提供给驾驶人员。
?Newton’s first two laws hold only when they are observed in unaccelerated reference frames.?牛顿第一、第二定律，只有在非加速的参照系中作观察时，才能成立。 ?When pressure is applied to ice, part of it will melt.?假如对冰加压，一部分冰就会溶化。 ?（三）until 和till 引导的时间状语从句的译法
?1．顺译法?英语中until 和till 引导的时间状语从句多位于句尾（偶尔也有位于句首的），汉译时通常按照其原文的词序仍然译在主句之后，所以称为顺译法，译为―直到……‖、―一直……为止‖、―在……以前……一直……‖等。如：
?This process continues till an equilibrium is established.?这个过程持续下去直到达到平衡。?The temperatures of its parts change until the whole rod is at 45℃.?它的部件温度会变化一直持续到整个棒都在45℃。?This sound keeps going until it hits a new layer of mud or soil.?这部分声音继续传播，直到碰到新的泥层或土层。?Electric machines are operated until failure occurs.?电机在发生损坏以前一直运行着。
?Until radar technique was used in astronomy, Man’s knowledge of Venus was still very superficial.?雷达技术应用于天文学以前，人类对金星的了解还极为肤浅。
?When the water temperature is increased, it vaporizes more quickly until it reaches boiling point.?水温升高时，水蒸发得越来越快，直到达到沸点为止。 ?2．倒译法
? 如果主句是否定句，即not…until / till（相当于not…before）句型，汉译时则一般将原来位于句尾的从句译在句首，译为―直到（后） ……才……‖，―在……以前不‖，如： ?The path is not completed till wires are connected. ?直到导线接上后此电路才接通。
?Do not wire-lock the adaptors until all tests have been satisfactorily completed. ?在圆满完成所有的试验之前，不要用保险丝将接头锁紧。
?It was not until the high-altitude rocket was invented that the direct exploration of the upper atmosphere became possible.?直到发明了高空火箭之后，直接探索上层大气才成为可能。 ??（四）once引导的状语从句的译法?once 引导的状语从句可以表示时间或条件，可译为―一旦‖、―一经‖、―如果‖等，如： ?Once it shows any sign of inhibition, the temperature must be raised.?一旦出现任何抑制的迹象，则应提高温度。
?The magnesium has to be warmed to start a rapid reaction, but once (it is) started, large quantities of heat and light energy are liberated.
?镁必须予以加热才能发生迅速反应，但反应一经开始，就有大量热和光能放出。?Once the piston begins its cushioning stroke, oil erupts from all orifices at once.?一旦活塞开始其缓冲行程，油立即从所有孔口喷出。
?An object, once it is in motion, will persist in that motion because of its inertia. ?物体一经运动，由于惯性就将继续保持其运动。 ?二、原因状语从句的译法
?（一）前置法?所谓的前置法，就是无论原文中的原因状语从句位于句首还是句尾，译文中均将原因状语从句译在句首，如：?Because each gene has it own unique sequence of
different DNA subunits, the precise sequence can be registered.?因为每个基因的不同的DNA副族都有自己的独特的序列，这一精确的序列可以注册。
?The various types of single-phase ac motors and universal motors are used very little in industrial applications, since polyphase ac or dc power is generally available.
?因为通常有多相交流电源或直流电源可用，因此，在工业上很少使用各种类型的单相交流电动机和交直流两用电动机。?Seeing that heat can be used to drive machines, it is a form of energy.?由于热能够用来驱动机器，所以它是一种能。
?The much discussed takeover by LCD monitors is still a few years away as an obvious price difference between equipment CRT and LCD models still exists. ?由于相同尺寸的CRT与LCD显示器之间仍存在很大的价格差异，人们议论颇多的由LCD显示器取代CRT还将需要几年的时间。?As the nature of the soil often varies considerably on the same construction site, the capacity of the soil to support loads also varies.
?即便在同一施工场地，由于地基的性质有很大差异，土体的承载力也不相同。?Since the secondary winding is normally operated into a high-impedance circuit, the secondary current is quite small.?因为次级绕组通常被输入高阻抗的电路，所以次级电流很小。
?从以上例句可以看出，所谓的前置法就是无论英语原文中原因状语从句位于句首还是句尾，汉译时均按照汉语的表达习惯译在句首。? ?（二）后置法 ?所谓的后置法，就是将原因状语从句译在句尾，如：?The out put power can never equal the input power, for there are always losses.?输出功率绝不可能等于输入功率，因为总有损耗。?A diode can be used as a rectifier because its current flows in one direction.?二极管可用作整流器，因为电流在二极管中只朝一个方向流动。?The material first used was copper for the reason that it is easily obtained in its pure state.?最先使用的材料是铜，因为纯铜易于炼取。?Ductility is also important because it is a measure of that property of a material which permits it to be cold-worked.?塑性之所以重要还因为它是材料冷作性能的衡量尺度。?Women of child-bearing age are at greatest risk, since their monthly bleeding is a major source of iron loss.?育龄女性危险最大，因为月经是铁流失重要原因之一。?Among the advantages of this system is the almost complete elimination of the need for pesticides and herbicides, as the controlled conditions reduce the possibility of pests and diseases.?这一系统的优点之一就是几乎完全不需要杀虫剂和除草剂，因为受控条件减少了病虫害产生的可能性。?以上例句可以看出，在英语原文中原因状语从句多位于句尾，其意义在于对结果的补充说明，汉译时采用后置法（或称为顺译法）将从句保留在后面。
?三、地点状语从句的译法?英语中引导地点状语从句的连词较少，仅有where，wherever等。地点状语从句的译法有如下两种情况。?（一）顺译法?翻译地点状语从句大都采用顺译法，即在英语原文中，如从句位于句首，则译文也位于句首；反之，若英语从句位于句尾，则译文也位于句尾。但有时根据情况需要，也可将位于主句后的地点状语从句译于汉语句子的句首。如：?Where it is required to produce flanges, some of the methods already given may be used.?在要求制成凸缘的地方，可以使用前面说过的某些方法。?Where such columns etc. are spaced at close intervals, it is often more practical to provide a continuous concrete strip foundation to carry a complete row, as is done for load bearing