oil lamp wick Financial staff are used to dividing the investment payback period into long-term, intermediate and short-term periods. The term usually refers to more than five years, short term generally refers to a period of less than one year, and the middle term is somewhere in between. Managers also use long, medium and short term to describe the plan. Long-term plan describes the organization in a quite long period (usually more than 5 years) and the development direction of policy, regulation on the group's various departments over a longer period of time in some activities should reach the goal and requirements, mapped the organization long-term development blueprint. Short-term plans specifically provides for all departments of an organization in the current stage, to the future the shorter period especially in the recent period of time, which should be engaged in activities, engaged in such activities should meet the requirement, and thus provides a basis for the ACTS of all members of the organization. "Conceptual framework" published by the financial accounting standards board Hybrid cars, which add an internal combustion engine to pure electric vehicles, aim to reduce the pollution of cars and improve the mileage of pure electric vehicles. Hybrid vehicles have serial and parallel structure.