Gasoline is produced and sold according to the brand name, and the specifications of the brand are regulated by national gasoline product standards and are related to different standards. At present, there are 3 gasoline license plates in China (IV), which are 90, 93 and 97 respectively. The state (V) is 89, 92 and 95 respectively (98 in the appendix). The number of gasoline is divided by octane number. For example, gasoline on 97 refers to a gasoline fuel equivalent to 97 percent of isooctane and 3 percent of n-heptane resistance. The larger the label, the better the anti-knock performance. Depending on the engine compression ratio, you should choose the different brand of gasoline, which will be indicated on the manual of each vehicle. A mid-range sedan with a compression ratio of 8.5-9.5 should generally use the 90 (country IV) gasoline, and the car with a compression ratio of 9.5 should use the gasoline of 93 (country IV). In finance, investing means buying securities or other financial or paper assets. Valuation is a way to estimate the price of a potential investment. The types of investments include real estate, securities investment, gold, foreign currency, insurance or bonds or stamps. These investments may then provide future cash flows that may increase or decrease their value. The investment in the stock market is carried out by securities investors. Investors are confused and lost on the way forward, the confusion and bewilderment itself will keeps everyone to learn, so investors are eager to learn has been exist, is the power of the instinct of the profit will lead us to learn. It is not easy to learn the key question is: futures, its difficulty may not be less than the difficulty of the transaction, this kind of difficult to make a lot of people were forced to study only a period of time, that then is in a state of flow for a long time, but it is difficult to further more in-depth study. V6 engine