All kinds of main relationship between natural technology conditions and coal cost are analysed, and the influence degree of costvariations resulted from the influence factors is determined.
分析了各种主要的自然技术条件与原煤成本变化的关系，由此确立了各影响因素对成本变化的影响程度。
2
The poverty indicator does not account for programmes that help the poor, such as the earned-income tax credit, nor does it adjust for regional variations in the cost of living.
贫穷指标没有将帮助穷人的项目包含在内，比如收入税收抵免，也没有为生活成本的地区不同而作调整。
3
For these reasons, and because of the additional time and cost involved in taking such variations into account, people often avoid using females in their research.