A historical experiment. In 1934, the Chrysler corporation of the United States first adopted a streamlined body design. In 1937, German design genius fernand porsche began designing cars resembling the beetle. Not only did the beetle crawl on the ground, but it also flew in the air, and its physical resistance was small. Dr Porsche maximized the merits of the beetle's appearance, making "vw" cars the representative work of streamlined cars at the time. The "golden age" of the beatles was the "golden age" of the car from the 1930s to the late 1940s. In November, AdDuplex released its November Surface device share data, where the Surface Pro 4 is currently the most popular product, accounting for 39.7% of Surface devices. The newly released Surface Pro(2017) accounts for 9.2%, roughly the total of the Surface Book(7.5%) and the Surface Laptop (2.0%). Under the theoretical framework of the theory, the theory of commodity market equilibrium and the monetary market equilibrium of Keynesian theory are unified. Marx's theory of interest rate decisions from the perspective of the source and essence of interest, taking into account the institutional factors in the role of interest rate decisions of interest theory, its theoretical core is the interest rate is determined by the average profit margin. Marx believed that under capitalism, interest is a part of profit and a form of conversion of surplus value.