项目MRP的需求来源只能是（）
A.产品预测
B.销售订单
C.采购订单
D.计划订单
参考答案：B
Mary kept weighing herself to see how much _____ she was getting.
A．heavy
B．heavier
C．the heavier
D．the heaviest
我国降水的时空变化和河川径流的时空变化的关系。
