Inconveniently, different products had curves of a different slope and different sources of cost reduction.
对于不同的产品，其经验曲线的走势千差万别，成本削减的原因也各有千秋。
2
The slope of the production possibilitiesfrontier reflects opportunity cost, because it describes whatmust be given up in order to acquire more of a good.
生产可能性坡边疆反映机会成本，因为它描述了必须放弃，以取得更多的好。
3
For prevention of pit side slope caving in, the paper adopts protection methods of pit side slope wood pile of construction simplification, low cost, ensuring safety.