采用Top-down方法估算铅的In-use stock案例中,建立铅消费量P与投入使用的物质量U间定量联系的最主要理由是( )In the case study that the in-use stock of lead is estimated by top-down method, which of the following describes the main reason for establishing a quantitative relationship between lead consumption P and lead entering Use stage U()
A.
物质消费量数据较投入使用的物质量数据更具有可得性 The data for material consumption is more available than the data for material entering Use stage
B.
物质消费量较投入使用的物质量更接近“使用”阶段 The material consumption process is closer to the Use stage than the process of material entering Use stage
C.
物质消费中更容易形成库存量 It is easier to form a material In-use stock in the material consumption process
D.
物质消费量与贸易量无关 Material consumption is independent with the trade volume