operating profit margins It can be seen that shares and shares are the relationship between form and content and cannot be confused. Additionally, some businesses tend to omit or neglect the after-sales service. /After putting the money into the pocket, businesses shoulder no responsibility for the successive service. This narrow-minded view wipes off the potential business based on customers' impression. When Businesses have been immersed in counting the temporary money, they have failed to gain more in future. /For example, the diamond of shoes from ABC I had purchased dropped off in two days. I had to head for the relevant repairing center. However, the repaired shoes broke again and irritated me to ask for the refund. What's more, they even charged more for the refunded money. Later I sworn never to offer a glance at this shop and dissuaded friends from visiting it. The customer's feeling directly decides on products' life in the market. 5. Accounting earnings depend on the reasonable proportion of income and expenses during the period. Costs that are not associated with the current period should be incurred as assets to be transferred for later periods. 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.