advantages and disadvantages of retained profit The capitalist mode of production first developed from industry and gained dominance, then gradually expanded to agriculture. Because there are two kinds of monopoly in the agriculture, the monopoly capitalism and operation of land and land ownership of monopoly, so it does not have such as like the sort of free competition in the industry, thus hindering the average profit margin. Therefore, the excess profit in agriculture is converted into rent. First, the individual production price of land products is lower than the social production price. The second is absolute rent from the value of land products beyond the price of social production. Both rent entity, agricultural employment is part of the surplus value created by laborer, it embodies the land owners through agricultural capitalist production relations of common exploitation agricultural workers. On the surface, however, the rent is distorted as the value of the land itself, or the gift of nature, thus disguising the real class relationship completely. The accounting income follows the historical cost principle and the matching principle, which is conducive to the objective reflection of the business management responsibility of the enterprise management authorities. But, due to the historical cost principle inherent defects, especially according to the present value of revenue and expenses by historical cost line, makes the calculation of accounting earnings lack of inner logical unity, and the matching principle is difficult to carry out, so that the book value of assets can not reflect its real value, cost cannot be fully compensated. And the economic benefit is measured in the current value, which reflects the actual value of the asset, which is beneficial to the full compensation of the cost. In the fifth stage, the national standard of motor vehicle gasoline is equivalent to the current standard in Europe, which meets the requirements of the standard of gasoline vehicle pollutant emission in the fifth stage. According to the ministry of reform, the ministry of finance and the ministry of environmental protection, the ministry of environmental protection and the ministry of environmental protection issued a notice on the issuance of a plan for the upgrading of refined oil products, and expanded the scope of the implementation of the five standards of automobile and diesel oil. Starting from January 1, 2016, China's eastern region is fully supplied with five standard vehicle gasoline (including E10 ethanol gasoline). Starting from January 1, 2017, the nationwide supply of motor vehicles (including E10 ethanol gasoline) that meet the standard of China's fifth standard will be fully supplied, while the domestic sales of the five standard vehicles will be stopped at the same time. Mehrotra said the additional rate for PC flash drives in 2017 is about 35 percent, and will increase to 75 percent by 2020. And "a lot of hard drives still need to be replaced by SSDS... Future self-driving vehicles are expected to be equipped with about 40GB of DRAM... This will also drive the use of NAND flash memory." In just three days, the yield on the 30-year Treasury bond jumped 16 basis points, the biggest gain since December 2008. The two-year - 30-year spread widened at the fastest rate since last year's U.S. election. This week the yield curve flattens out. Is it a short adjustment or a bear market start? Earlier this year, the average five-year Treasury note paid 1.67 percentage points, compared with 2.02 percent today.