advertising On the basis of introducing marginal concepts and mathematical argumentation, neoclassical has established a formal "perfect" mathematical model for the neoclassical "laissez-faire order" : general equilibrium. The price is the most important independent variable in this model, which can also be called price mechanism. The process of achieving general equilibrium is also a process of social resources guiding the flow of prices, so the price mechanism regulates the allocation of social resources. 4. The determination of accounting earnings shall follow the principle of revenue confirmation. The current accounting practice and the law's view of earnings are still: only after the relevant conditions of the asset value increase are met, the benefits can be generated. Income and appreciation must be measured objectively, determined or unalterable, and must be verified through some business or accounting matters. In other words, the determination of accounting income should be based on the following two principles: the realization principle of income determination and the prudent principle of income determination. According to the realization principle of revenue recognition, the enterprise income should be divided into operating income and profit and loss. The determination of operating earnings must happen in selling goods or services and other key issues, and the profit and loss refers to the production of the assets held realized gains and losses, unrealized gains and losses caused by price change is not confirmed. According to the principle of steady earnings determine when a has a variety of economic business accounting methods for when the choice, should choose the most don't overestimate the method of income, it should not be overestimated revenues and should not be underestimated cost two aspects. Historically, the concept of income has first appeared in economics. Adam Smith, in the wealth of nations, defined income as "the amount of consumption that is not eroded by capital", and saw it as an increase in wealth. Later, most economists inherited and developed this view. 1890, ai (Alfred Marshall Maarshell) in its "the principles of economics," the Adam Smith's "wealth increase" enterprise, introduced the concept of earnings, is proposed to distinguish the entity capital and value-added benefits of economic benefits. Microsoft's Surface Pro, Surface Laptop, Surface Book and Surface Studio are the main products of Microsoft's Surface series, but there is a clear difference in the share of the devices. The Surface Pro products account for the highest share (79.9%), the Surface Book (7.5%), Surface Laptop (2.0%), and Surface Studio (0.2%). Data released by the American petroleum institute (API) showed that U.S. crude oil inventories fell 5.2 million barrels in the week ended Dec. 15, down from an expected 35.18 million barrels. Refinery inventories fell more than expected, while gasoline inventories rose, but were less than expected. The overall API data is good and good for oil prices. It doesn't seem to be too much of a market to really focus on learning or learning about the importance of learning. More and more, I feel that learning is to keep to the only way to do it for a long time in the market, continuous learning can bring something new to you constantly, in a sense, the ability of learning will be able to represent your trading ability and analysis ability.