Thus in computing the contribution, only those costs which vary directly with the level of activity within a relevant range are used. (However, it is not always easy to distinguish costs as either fixed costs or variable costs.)
因此在计算边际贡献时只使用那些在相关范围内直接随产出水平而变动的成本(但是,变动成本和固定成本之间的区分并非总是那么容易)。