call center profit margin 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.  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. Hybrid car Gasoline English called Gasoline (beauty)/Petrol (UK), appearance is transparent liquid, inflammable, distillation range of 30 ℃ to 220 ℃, main components in C5 ~ C12 fatty hydrocarbon and naphthene classes, and aromatic hydrocarbon, certain amount of Gasoline with high octane number (antiknock combustion performance), and by the discretion of octane number can be divided into no. 90, no. 93, no. 95, no. 97. Straight-run gasoline components which are obtained by oil refining gasoline, catalytic cracking gasoline, catalytic reforming gasoline components such as different after refined gasoline with high octane number components made by the harmonic, mainly used in automobile ignition internal combustion engine fuel.