(3) monetary benefits -- increase the monetary value of assets. There are both measurable and unquantifiable benefits in these three different forms of income. Among them: mental income is too strong to measure, monetary gain is easy to measure because of the static concept of value change. Economists, therefore, focus only on actual earnings. Understand different connotation of interest rates, will help us for the financial concepts of interest rates has a more deepen understanding, especially the formation, change and derivatives need to be determined by the market, this is a very key factor. Now, however, that wisdom is being questioned, not just in Britain. As long as inflation is a real and present danger, it makes sense to put monetary policy down to the conservative central bankers and keep them from the government's fiscal deficit. Instead, the problem today is the opposite: that the central bank cannot raise inflation to its target. In 1934, professor rei, of the center for fluid mechanics, used model cars to measure the aerodynamic drag of various bodies in wind tunnels