I didn’t like the color of the coat my mother bought me, so she went back to _______ it for another one.

A．replace

B．exchange

C．afford

D．measure

计划成本是按计划期内平均定额水平计算的，而定额成本是按现行定额计算的；计划成本反映平均水平，定额成本反映当时应达到的水平。