There is no risk of this arbitrage. Range and once the two currencies yield, the yield of arbitrage mechanism will make two currencies are equal, that is, different interest rates in the currency of the country there is inherently a trend towards an equalization and trend, it is the interest rate index key aspects of the impact of foreign exchange to, also is our interpretation and grasp the key interest rate index. Among them, the repeal of the affordable care act means obamacare will be repealed, and the tax reform bill has essentially repealed obamacare. The media is expected to sign a tax reform bill on January 3 that would make it a bill. Historically, the concept of income has first appeared in economics. Adam Smith, in the wealth of nations, defined income as "the amount of consumption that is not eroded by capital", and saw it as an increase in wealth. Later, most economists inherited and developed this view. 1890, ai (Alfred Marshall Maarshell) in its "the principles of economics," the Adam Smith's "wealth increase" enterprise, introduced the concept of earnings, is proposed to distinguish the entity capital and value-added benefits of economic benefits. Competition refers to the economic subject in order to maintain and expand their own interests and take all sorts of behavior, the behavior of self-protection and expansion efforts in product quality, price and service advantages, varieties, etc. The bank maintained its main interest rate by 0.0 percentage point and raised its 2017 GDP growth forecast by 2 percentage points to 2.4 percentage points.