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. But administrators lost £990 a year compared to full-time employees and the average sales or customer service worker lost £800 a year. Based on the above two kinds of comparison and analysis of the concept of earnings, reveals the inadequacy of accounting earnings, i.e., the accounting income does not take into account inflation, the production gains, goodwill to improve the impact of changes and their value, and can be found on only the pursuit of reliability, and can be measured, which affect the enterprise's profit ability and continuous operation ability. Accounting, since the 1950 s began to pay attention to absorb the income concept of some reasonable kernel of economics, the concept of modern accounting theory of income in the income concept of economics. On Wednesday, on the first four shopping days of Christmas, upscale stores were discounting heavily, including most of the fashion retailers. H&M offers discounts of up to 60%, while Debenhams, Fraser, French connections, gaps, new faces and Dorothy Perkins offer discounts of up to 50%. According to the length, there are mini passenger cars (no more than 3.5 meters), small passenger cars (3.5-7 meters), medium-sized buses (7-10 meters) and large passenger cars (more than 10 meters).