According to the engine displacement, divided into a miniature (1 liter), light level sedan (1-1.6 liters), intermediate (1.6-2.5 litres), senior sedan (2.5 4 liters), limousine (4 liters). According to the engine displacement, divided into a miniature (1 liter), light level sedan (1-1.6 liters), intermediate (1.6-2.5 litres), senior sedan (2.5 4 liters), limousine (4 liters). Interest rate, in the form of expression, refers to the ratio of the amount of interest to the total amount of borrowed capital in a certain period of time. [1] the interest rate is the interest level per unit time of the unit currency, indicating the interest rate. Economists have been looking for a theory that can fully explain the structure and change of interest rates. Interest rates are usually controlled by the central bank of the country and administered by the federal reserve board in the United States. Today, interest rates are one of the important tools for macroeconomic regulation. "People say 'oh, those experts', but we're seeing what we call potential risks being rolled out. This is not what the experts say, this is what the economy is showing. " 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%). But the DRAM and NAND semiconductor industries have gone from boom to bust in the face of rising prices and the abundance of falling prices. Will it be any different this time? Or is the need for mobile device memory and disk replacement sufficient to continue to delay the abundance until the foreseeable future?