1、应正确使用外文字母的正斜体、黑白体、大小写和上下角标,以免发生误解,如“t”(吨)与“t”(时间)、“V”(伏[特])和“V”(体积)不可混淆。2、外文字母正体的常用场合:1计量单位符号和SI词头。2数学式中的运算符号、指数和对数函数符号、特殊常数符号、缩写符号等,如Σ(连加),e、ln(自然对数),lg(常用对数),lim(极限),π(圆周率),max(最大值),min(最小值)等。3生物学中亚族以上(含亚族)的拉丁文学名及定名人。4化学元素符号。5仪器、元件、样 1, correct use of foreign alphabets are italic, black and white, upper and lower case, avoid misunderstanding, such as “t ” V [special]) and “V ” (volume) can not be confused. 2, Foreign letters are used in common body: 1 unit of measure and SI prefix. 2 math symbols, exponential and logarithmic function symbols, special constants symbols, abbreviations, etc., such as Σ (with added), e, ln (natural logarithm), lg (common logarithm), lim , π (pi), max (max), min (min) and so on. 3 biology in the Asians (including Asians) Latin names and celebrities. 4 chemical element symbol. 5 instruments, components, like