friendly motor cars Modern economy, the interest rate as the price of money, not only restricted by many factors in the economic and social, and changes in interest rates to have a great impact on the economy as a whole, as a result, modern economists are studying the interest rate decision problem, pay special attention to the relationship between the variables and the balance of the economy as a whole, the interest rate decision theory has experienced the classical interest rate theory, Keynes's interest theory, interest rate in loanable funds theory and is-lm analysis as well as the contemporary evolution of dynamic interest rate model, the development process. In terms of the importance of the plan, the plan can be divided into strategic planning and operational planning. Yu 'ebao, the world's largest money fund, took only four years to achieve the equivalent of 10 years of development, with a maximum annual yield approaching 7%. But in its rapid development, there have also been a big wave of backwater, the most severe, from March 2015 to September 2016, the yield was down from 4.4 percent to about 2.4 percent. The importance of gasoline was not recognized in the 19th century, when it was used in a great deal of kerosene. The oil refining then relied on simple distillation processes to separate the different components of the oil from the boiling point. The boiling point of the kerosene component is higher, and the use of safety when lighting lamps becomes the main product of crude oil refining, while gasoline and other components are often burned as fuel. By the mid - to late 19th century, the successful use of gasoline engines in 1886, in 1886, the gasoline engine was successfully used as a driving force, thus the importance of gasoline increased. But using distillation, only 20% of the gasoline can be extracted from crude oil. In 1911, the standard oil company have solved the problem of low gasoline yield, by William burton and Robert hamm forest thermal cracking process of the invention, the heavy quality heating gas oil cracking of light gasoline fractions, such as to overall improve the gasoline yield, thermal cracking process in 1913 won the patent license in the United States. The subsequent catalytic cracking process has further improved the gasoline yield and octane value.