Workers in the category for caring, leisure and other service occupations earn £218 more on average than equivalent full-time members of staff, while temporary managers and directors enjoy a £2,477 pay boost compared to full-timers. The American petroleum institute (API) released data showing a decline in U.S. crude oil and refined refining inventories, while gasoline inventories rose. Stocks and shares are closely linked and different. In the early 20th century, famous American economist elvin fisher developed the theory of economic gain. In its book "the nature of capital and yield", first, the concept of yield is analyzed in terms of the performance of earnings, and three different types of benefits are proposed: 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.