The decision model proposed is different from traditional models and variableexpense, not variable cost, is considered.
与传统的模型不同，本文建立的决策模型中考虑了变动费用，而不是变动成本。
2
We need to know that energy consumption represents the single largest controllable operating expense for a building, typically a third of variable expenses.
我们应当认识到，能源消耗是建筑物的唯一一项最大的但可控制的营运费用，一般为可变费用的三分之一。
3
All electronic SS type camera tube is characterized by its low expense of power, variable scan frequency, high resolution, small size and light weight.