连词or可用于表示两个或多个选择，也可以表达同义或等效的意思。当作后者用时，or可视作also referred to as（也称为）、defined as（定义为）或in other words（换句话说）。分别举例如下
：
例句一：Infrared spectroscopy or electron paramagnetic resonance spectroscopy can be used to follow the kinetics of radical decay.
此句属于or的第一种用法，即连接两种不同的技术—红外线光谱技术与电子顺磁共振光谱技术，此两种技术均可用于追踪自由基衰变的动态轨迹。
例句二：Reflectance difference spectroscopy or reflectance anisotropy spectroscopy is a powerful tool for characterizing the surfaces of crystalline materials.
例句二很容易被解读为，reflectance difference spectroscopy与reflectance anisotropy spectroscopy为两种不同的技术。然而，reflectance difference spectroscopy与reflectance anisotropy spectroscopy是同一种技术的两个惯用称呼，因此此处的or不同于例句一，实际上是also referred to as（也称为）的意思。为避免歧义，可采用逗号将or连接的第二个术语同主句其他部分分隔。
例句三：Reflectance difference spectroscopy, or reflectance anisotropy spectroscopy, is a powerful tool for characterizing the surfaces of crystalline materials.
您可能会认为逗号是没有必要的，因为有专业背景的读者知道这两个术语指的是同一技术。然而，使用逗号的表述方法，会有助于没有专业背景的读者掌握句意。若您不想用逗号分隔，您亦可以做如下的修改：
例句四：Reflectance difference spectroscopy, also referred to as reflectance anisotropy spectroscopy, is a powerful tool for characterizing the surfaces of crystalline materials.
以下是类似例句三中or用法的一些例句：
例句五：We used quasielastic, or dynamic, light-scattering spectroscopy to assess the sizes and polydispersities of the particles.
例句六：The dihydropteroate synthase gene is part of the folic acid synthesis gene, or fas gene, and encodes a trifunctional protein.
例句七：Binding immunoglobulin protein (BiP), or 78-kDa glucose-regulated protein (GRP-78), is highly induced in hypoxic tumors.
例句八：We studied the mutarotation, or change in optical rotation accompanying epimerization, of 8-ᴅ-galactopyranose in dilute aqueous buffer (pH 4.3) at 15°C.
涉及and连接的并列主语中出现介词短语时的错误
当用and连接两个主语，且其中第一个主语包含介词短语时，可能会导致句意歧义。以下是我最近编辑的一篇化学论文中的句子：
例句九：Data processing for reproduction of element maps and calculation of fluorescence counts was performed with the software package.
介词for后短语的出现会引起歧义。该软件执行了什么操作？是正如使用单数动词形式was所暗示的，仅仅是数据处理? 还是作者是指该软件应用于数据处理与计算？也就是说，作者的意思是：
Data processing... and calculation... were performed with the software package.
而不是：
Data processing for reproduction... and for calculation... was performed with the software package.
作者会觉得熟悉电脑程式，或元素图与荧光计数的读者，应该会一目了然句子传达的意思。但为什么不让句意更直接明了呢？若您想表达data processing是主语，则可以重复介词for，即采用并列的介词短语来修饰限制主语：
例句十：Data processing for reproduction of element maps and for calculation of fluorescence counts was performed with the software package.
若为双主语，只需要调整句中名词短语的顺序即可：
例句十一：Calculation of fluorescence counts and data processing for reproduction of element maps were performed with the software package.
若想进一步简化，也可以删除例句十一中主语短语中的介词of：
例句十二：Fluorescence count calculation and data processing for reproduction of element maps were performed with the software package.
有时候，将被动语态转变为主动语态也能收到不错的效果：
例句十三：We used the software package to process data for reproduction of element maps and to calculate fluorescence counts.
我们再来看另一个复杂的句子：
例句十四：Node I, the culms between node I and the rachis, the flag leaf blade, and the panicle were dried separately.
像我一样不熟悉植物解剖学的读者，可能会一时分辨不清，句中有四个并列主语（node I、culms、blade及panicle）还是只有两个（node I及culms）？若为两个并列主语（node I及culms），则可以借由介词between来阐释：
例句十五：Node I and the culms between node I and the rachis, between node I and the flag leaf blade, and between node I and the panicle were dried separately.
若为四个并列主语（node I、culms、blade及panicle），最简单的陈述办法是用分号来区隔：
例句十六：Node I; the culms between node I and the rachis; the flag leaf blade; and the panicle were dried separately.
亦可以通过将culms＋介词短语的主语放在最后，以清楚说明四个并列主语结构：
例句十七：Node I, the flag leaf blade, the panicle, and the culms between node I and the rachis were dried separately.
校稿时，最好能做到以读者的立场来审视文稿，即抱持着怀疑态度，找出虽无语法错误但却可能会被误解的句子。
