small oil leak The importance of gasoline was not recognized in the 19th century, when it was used in a great deal of kerosene. The oil refining then relied on simple distillation processes to separate the different components of the oil from the boiling point. The boiling point of the kerosene component is higher, and the use of safety when lighting lamps becomes the main product of crude oil refining, while gasoline and other components are often burned as fuel. By the mid - to late 19th century, the successful use of gasoline engines in 1886, in 1886, the gasoline engine was successfully used as a driving force, thus the importance of gasoline increased. But using distillation, only 20% of the gasoline can be extracted from crude oil. In 1911, the standard oil company have solved the problem of low gasoline yield, by William burton and Robert hamm forest thermal cracking process of the invention, the heavy quality heating gas oil cracking of light gasoline fractions, such as to overall improve the gasoline yield, thermal cracking process in 1913 won the patent license in the United States. The subsequent catalytic cracking process has further improved the gasoline yield and octane value. At present, about the nature of the enterprise. Western economists have different views. There is also some debate. Some western economists analyze the nature of the enterprise mainly from the perspective of transaction costs that coase emphasizes. The Resolution Foundation said the loss of pay across all sectors took the average loss for each of the UK’s 800,000 agency workers to £500 a year, up from £430 last year. From the end of the 19th century to the early 20th century, car designers focused their energies on the development and innovation of mechanical engineering. First half of the 20th century, all about the basic structure of the car has been invented, automotive designers begin from the outside to improve on modelling, and successively introduced the aerodynamics, fluid mechanics, human body engineering and industrial modelling design (industrial aesthetics), etc In terms of the purchase of intermediate products in the market, because a lot of manufacturers are generally buy goods from a handful of suppliers, it is beneficial to this a few suppliers to achieve economies of scale and reduce the cost of production. Moreover, market competition pressure between intermediate product suppliers forces suppliers to reduce production costs. In addition, when a few suppliers in the face of many intermediate products of demanders, these a few suppliers can be avoided due to the limited market demand caused by unstable, the loss that may lead to maintain a stable overall sales. But how long can anyone support "god and the gun" at the cost of "bread and butter"? The meditationist populists who presided over the Roman empire knew that the populist mob needed material and diversion: bread and circuses. Angry twitter makes no sense to those who can barely afford to live with dignity, let alone tickets to the modern Colosseum to watch football matches.