When using expenditureapproach identity to measure the contributions of its components to GDP, the result is that net export only contributes a little to GDP, or import contributes negative to GDP.
Polyacrylamide has not harmful effect on environment. In addition, its input expenditure is low. This new approach of preventing soil and water losses is deserved exploring deeply.
施用聚丙烯酰胺对环境无不良影响,而且投入费用较低,是一条值得探索的防治坡地水土流失的新途径。
3
We mainly use production approach and income approach, also develop expenditure accounting approach.