most profitable company "British shoppers more savvy than ever before, and ready to search the best deals on the net, the gimmicks and discount stores provide more and more sensible, many people now realize that may not be as they first appear. Compression ratio refers to the ratio between the total volume of the cylinder and the volume of the combustion chamber, which indicates the degree of gas compression in the cylinder when the piston moves from the lower stop to the upper stop. Compression ratio is an important parameter to measure the performance of automobile engine. 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.