profit and losses (1) spiritual gain -- spiritual satisfaction; Generally speaking, the interest rate varies according to the term of measurement, indicating that the method has annual interest rate, monthly interest rate and daily interest rate. This week, interest rate debt in developed countries in Europe and the United States suffered a massive sell-off. Affected by this, the yield curve of government bonds has been changed to a steep and steep trend. “We are a trade specialist so all retail enquiries and enquiries from smaller independent installers are handled by our customers, which means they are sharing directly in the success of our campaign.” (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.