In order to overcome the rear overreach of the ship's car, a strong air eddy effect was created when the car was traveling at high speed, and people developed fish shaped cars like the back of a fish. In 1952, general motors' buick sedan ushered in the era of fish cars. In terms of the shape of the car's back, a fish-type car is similar to a beetle. But as observed carefully, will find fish type car back and ground into the Angle is small, the tail is longer, around the body of the air flow is relatively easier, so vortex flow resistance is also relatively small. Wedge car 2. Accounting earnings are based on the assumption of accounting instalments, which refers to the production and operation results of a certain period of time. Early accounting earnings is calculated according to the cash basis, and the modern accounting earnings is according to the classification current income and expenses of accrual basis, after the appropriate ratio calculated. However, the benefits of cash determination are more acceptable to users. With the development of productivity and social progress, the enterprise form has been continuously developed and improved. The evolution of an enterprise mainly goes through three stages In 2018, we must: There is no ambiguity in the objective of the concrete plan. For example, business sales managers intend to increase sales by 15 percent over the next six months, and he will formulate specific procedures, budget plans, and schedule schedules, which is the concrete plan. Guideline plans only some general guidelines and action principle, favors the actors free disposition, it points out that the key but don't limit actors on the specific target or specific action plan. For example, a specific plan to increase sales may require a 15 per cent increase in sales over the next six months, while a guidance plan may limit sales by 12 to 16 per cent over the next six months. Compared with the guidance plan, the concrete plan is easier to carry out, assess and control, but lacks the flexibility, and its requirements for clarity and predictability are often difficult to satisfy.