The euro zone's landmark buildings are seen at the headquarters of the European central bank (ECB) in Frankfurt In 1934, professor rei, of the center for fluid mechanics, used model cars to measure the aerodynamic drag of various bodies in wind tunnels The proposed acquisition of calcium chloride will improve the self-balancing ability of chlorine and alkali and guarantee the stability of industrial chain 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. Interest rates are an important tool for regulating monetary policy, and they are also used to control economic growth, such as investment, inflation and unemployment. Reasonable interest rate plays an important role in the economic leverage of social credit and interest rate.