This may have a negative effect on the sales of Xpoint products. In his theory, money supply is controlled by the central bank and is an exogenous variable with no interest rate elasticity. At this point, monetary demand depends on people's psychological "liquidity preference". 2. Leakage of gasoline pipe interface Because economists understand earnings as actual material wealth increase, accounting experts think the output value of more than the difference between the input value is profits, there is a contradiction and two kinds of income concept. The specific performance is: