In terms of the purchase of intermediate products in the market, because a lot of manufacturers are generally buy goods from a handful of suppliers, it is beneficial to this a few suppliers to achieve economies of scale and reduce the cost of production. Moreover, market competition pressure between intermediate product suppliers forces suppliers to reduce production costs. In addition, when a few suppliers in the face of many intermediate products of demanders, these a few suppliers can be avoided due to the limited market demand caused by unstable, the loss that may lead to maintain a stable overall sales. 1. The accounting income is based on the actual economic business of the enterprise, and the sales revenue obtained from selling products or providing services is deducted from the cost of actual sales revenue. These economic businesses include both external and internal transactions. Business activities with the outside world transfer the assets or liabilities of an enterprise, since it is usually a direct monetary income, so its measurement is generally accurate. The use or transfer of assets within an enterprise, as a result of a non-direct monetary balance, is usually not accurate. According to traditional accounting views, changes in market prices or expected prices are not included in the transfer of internal assets. When a transaction occurs, the price of an old asset is usually transferred to the new asset, which is the measurement of the proceeds of the transaction. The transaction method automatically deduces the process of determining income during sales or trading, as well as the cost transfer practice in accounting. ECB President Mario draghi said at a press conference following the central bank's board meeting that important changes had taken place in the resumption of negotiations. The theory of modern political economy in China holds that the profit under the socialist system is the form of the value of the surplus products created by the workers for the society. The value composition of the product is c+v+m,c+v is converted into production cost, and the m is part of the surplus product created by the laborer for the society, which translates into profit for the enterprise. The specific form of socialist profit is: to realize profit, that is, the balance of the sales revenue of the enterprise minus the expenses of various expenses; To pay the profits in accordance with the provisions to the national financial department; After tax profit, that is, the profit of the enterprise shall be returned to the enterprise in accordance with the state provisions.