It is worth mentioning that Surface Pro is by far the most popular with users of Surface equipment, Surface Pro 4 proportion is as high as 39.7%, Surface Pro 3 also is as high as 21.7%, while older equipment Surface Pro/Pro 2 still has 5.6% and 3.7% of the users. On the Surface Book, however, the average user accounts for just 0.4 per cent of the market, except for the 7.5 per cent share of the first generation, which may be due to a short listing. 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. The government also told the bank of England that it could increase its $25bn in regular funding schemes, which means that this is unlikely to change. (3) monetary benefits -- increase the monetary value of assets. There are both measurable and unquantifiable benefits in these three different forms of income. Among them: mental income is too strong to measure, monetary gain is easy to measure because of the static concept of value change. Economists, therefore, focus only on actual earnings.