“已知数”的英语可以翻译为：datum，known number ...

通过已知数可以算出未知数.The unknown number can be calculated from the data.反射允许在运行时检查已知数据类型.Reflection allows known data types to be inspected at runtime.在微分方程组中驱动力作为已知数, 所以驱动力直接影响着微分方程组的求解结果.The force is given in the differential ...