1. 用于表示十進制數的一種二進制編碼的十進制碼，其中每位十進制數用七位二進制數來表示，它們分別是8，6，4，2，0，1和0的系數。五－二碼表如下：
   A binary-coded decimal code for representing decimal numbers in which each decimal digit is represented by seven binary digits which are coefficients of8,6, 4,2, 0,1, 0, respectively.
2. 恒溫器是以不同的金屬有不同的膨脹系數這一事實為根據的。
   The thermostat is based on the fact that different metals have different coefficients of expansion.
3. 每個部門的開支必須屬于確定的系數之內。
   Spend by each department have to fall within certain parameter.

系的英語翻譯：

數的英語翻譯：