(75) is the budgeted amount for the work actually completed on the schedule activity or WBS component during a given time period.

A．Planned value

B．Actual cost

C．Earned value

D．Cost variance

以曲轴加工为例，说明为什么机械加工工艺性的评价应依据生产厂的生产条件，没有一个绝对的标准。