revenue cost and profit Microsoft's Surface Pro, Surface Laptop, Surface Book and Surface Studio are the main products of Microsoft's Surface series, but there is a clear difference in the share of the devices. The Surface Pro products account for the highest share (79.9%), the Surface Book (7.5%), Surface Laptop (2.0%), and Surface Studio (0.2%). Security is very important, reduce risk is big potential! Labour minister John MacDonald (John McDonnell), said the international monetary fund, according to a report of a conservative government "good at cuts in public services, tax breaks for a few rich people, but no hope to invest in our country for the majority of people skills and infrastructure needed for the economic development". Interest determines the regularity of prescriptive (interest this qualitative rules will determine the amount of the rules), the amount of interest depends on profit, interest rate depends on the average profit margin. Marx further pointed out that, between average profit margin and zero, interest rate depends on two factors: one is profit margin; The second is the proportion of total profits allocated between lenders and borrowers.