The current GB/T3730.1-2001 car is divided into passenger cars and commercial vehicles. In economic terms, the benefits of holding any two currencies should be equal in the equilibrium of the foreign exchange market, which is: Ri=Rj (interest rate parity). Here, R stands for yield, and I and j represent currencies of different countries. If the benefits of holding two currencies are unequal, you will have A arbitrage: buy A kind of foreign exchange and sell B foreign exchange. Value theory of the many contradictions and arguments, essentially derives from the different definitions of value, originated in the people for the different understanding of the concept of value, value, from the perspective of physics can put the theory of value based on the foundation of natural science, with a high degree of accuracy, objectivity and rationality, so that the value theory of widespread vagueness, subjectivity and ambiguity naturally are addressed. As social things all the movement and the change of value relation is in essence the motion and change, so the value theory is the foundation of social science theory, if the value theory is built on the basis of natural science, can greatly promote the fusion and unity of the social science and natural science, but also make the social science become subservient to the natural sciences. Then the interest rate theory of the loan is the interest rate theory of neoclassical school, which is proposed to correct Keynes's theory of "liquidity preference". In some ways, the theory of interest rate can be regarded as a synthesis of classical interest rate theory and Keynesian theory. But trump and republicans seem willing to take the risk. After all, by pushing the middle class to raise interest rates, they have already laid out plans for the 2018 and 2020 elections. From now on, they can boast about most family tax cuts. They are expected to peak in the run-up to the presidential election in 2019 and before the bill expires. Time factor a transaction's expected time is a question worth considering. The investment of securities provides an important means for the central bank to conduct financial macro-control, which is of great significance to the sustainable and efficient development of the national economy.