substituting butter for vegetable oil In the early 20th century, famous American economist elvin fisher developed the theory of economic gain. In its book "the nature of capital and yield", first, the concept of yield is analyzed in terms of the performance of earnings, and three different types of benefits are proposed: Originated in ancient human market trading place for a fixed period of time or place, after the urban growth and prosperity, live in the city of adjacent area farmers, craftsmen, artisans, will start to deal with each other and contribute to the economy of the city. Obvious, the best way to trade is in the city there is a centralized, as market, can let the people in the provision of goods and business services, convenient for people to find goods and business contacts. When a city's market becomes large and more open, the city's economic vitality is also relatively growing. Passenger car: in its design and technical features, it is mainly used to carry passengers and their carry-on luggage and (or) temporary items, including the driver's seat, not more than 9 seats. It can also draw a trailer. Classified into ordinary passenger cars, live senior passenger cars, passenger cars, small passenger car, convertible, warehouse back passenger car, station wagon, multipurpose passenger vehicles, short head special passenger cars, cross-country passenger cars and passenger cars, etc. 11 class. If interest rates rise in some currencies, interest gains on the currency will increase, attracting investors to buy the currency, so it is good for the currency. If interest rates fall, the gains from holding the currency will diminish, and the appeal of that currency will weaken. So you could say, "interest rate rises, strong currencies; Interest rates fall and currencies weaken. He added: "austerity has failed and will only continue to undermine our economy in the brexit negotiations. In a broad sense, interest rates are not limited to bank interest itself, but also to bond markets, and even to share dividends, another way of stating dividends. In fact, in the United States, the proportion of direct financing is far greater than the indirect financing, corporate bonds, debt-financed and publicly traded shares is a very important means of financing, at this time all can use the concept of interest rates for analysis.