constant cost的用法和樣例：
例句
- Your impatient self clearly suffers from a similar fixed cost of carrying out subtraction.
你身上那個(gè)急躁的自我，顯然在實(shí)施減法時(shí)承受著(zhù)類(lèi)似的固定成本。 - We may classify costs as variable cost and fixed cost for the purpose of planning and control.
為了計劃和控制，我們可以把成本劃分為固定成本和變動(dòng)成本。
