maryland non profits 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. 6. The accounting benefit is bound by the prudent principle. According to the principle of prudence, when there are a variety of accounting methods to choose from an economic business of an enterprise, it should choose a method that neither overestimates nor depreciates the benefits. Enterprises manipulate profits to achieve homogenization of profits, most of which adopt the method of overestimating earnings, and the subjective selection of the period of value-added. Profit is not only the same in quality, but also the essence of profit. Profit is the form of corporate profit, and is also equal in quantity. The difference in profit is that for variable capital, profit is for all costs. Once earnings into profits, therefore, the origin of profits and material production is made it is a reflection of the "(" the complete works of Marx and Engels in volume 25, page 56), and thus has the various forms of money. In capitalist society, the essence of profit is: it is the product of capital, it has nothing to do with labor. According to the engine displacement, divided into a miniature (1 liter), light level sedan (1-1.6 liters), intermediate (1.6-2.5 litres), senior sedan (2.5 4 liters), limousine (4 liters).