The "fish-type duck tail" model partially overcomes the lift of the air when the car is traveling at high speed, but it does not fundamentally solve the problem of lift of the fish. After a lot of exploration and experimentation, the designer finally found a new type of model - wedge. This type of vehicle is to tilt the body forward downward, and the back of the body is as straight as a knife, which can effectively overcome lift. Based on the above two kinds of comparison and analysis of the concept of earnings, reveals the inadequacy of accounting earnings, i.e., the accounting income does not take into account inflation, the production gains, goodwill to improve the impact of changes and their value, and can be found on only the pursuit of reliability, and can be measured, which affect the enterprise's profit ability and continuous operation ability. Accounting, since the 1950 s began to pay attention to absorb the income concept of some reasonable kernel of economics, the concept of modern accounting theory of income in the income concept of economics. Network planning technology was developed and developed in the United States in the late 1950s. This approach includes a variety of web-based methods, such as critical path method, planning review technology, combined network method, etc. "Manufacturing companies with complex and lengthy international supply chains, such as the automotive industry, could also face significant challenges. These developments could also have a significant impact on productivity growth. " This year, ms lagarde said there was a marked slowdown in activity and the UK's recent performance was The savings rate in January has fallen to historic lows since last August's cut in bank interest rates.