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: It is generally believed that the v-shaped engine is a relatively advanced engine, which also becomes a symbol of the sedan grade. At present, the most common engines are the straight-line 4 cylinder (L4) and v-type 6 cylinder (V6) engine. In general, the V6 engine has a higher displacement than L4, and the V6 engine runs smoothly and quietly than the L4 engine. A V6 engine is usually mounted on a mid-grade sedan. (1) spiritual gain -- spiritual satisfaction; For many, the first benefit of entering the blockchain and cryptocurrency world could be economic gain. The API said gasoline stocks rose by 200.10 million barrels last week, an increase of 2231, 000 barrels. Refining inventories fell by 2.58 million barrels last week, or 13.27 million barrels. But to increase political accountability and to sacrifice the independence of the central bank is to throw the baby out of the bath. Monetary policy is complex and technical. Handing control to politicians is more prudent than handing over keys to the country's nuclear power plants.