India's income tax authorities are sending a tax notice to half a million bitcoin users who are trading in encrypted currencies. Compression ratio refers to the ratio between the total volume of the cylinder and the volume of the combustion chamber, which indicates the degree of gas compression in the cylinder when the piston moves from the lower stop to the upper stop. Compression ratio is an important parameter to measure the performance of automobile engine. There are many types of plans that can be classified according to different criteria. The main classification criteria are: importance of plan, time limit, clarity and abstraction. However, according to these classification criteria, the type of plan obtained is not independent of each other, but is closely related. For example, short - term and long-term plans, strategic plans and job plans, etc. 3. The cost of accounting earnings is listed in historical cost. Due to the current accounting practice in the enterprise asset is measured at the historical cost in, with the cost nature is the historical cost has been derived from the law of the transfer, so as to determine the income is an important factor in the cost and the historical cost.