short run and long run profit maximization (1) car: a vehicle for carrying personnel (2-9 persons) and their carry-on items and their seats are arranged between the two axes Originated in ancient human market trading place for a fixed period of time or place, after the urban growth and prosperity, live in the city of adjacent area farmers, craftsmen, artisans, will start to deal with each other and contribute to the economy of the city. Obvious, the best way to trade is in the city there is a centralized, as market, can let the people in the provision of goods and business services, convenient for people to find goods and business contacts. When a city's market becomes large and more open, the city's economic vitality is also relatively growing. Similarly, while Mr Trump's rhetoric on immigration is intense, his policy is relatively moderate, probably because many businessmen who support his campaign do prefer a moderate approach. The "Muslim ban" does not affect America's Labour supply. Although the pace of deportation has accelerated under Mr Trump, it is worth mentioning that millions of undocumented immigrants have also been deported by Mr Obama. The border wall that Mr Trump has forced Mexico to pay remains a dream of no capital. Even if the government plans to favor skilled workers, it will not necessarily reduce the number of legal immigrants. First of all, it costs transaction cost for the manufacturer to purchase intermediate products in the market. It includes the cost of seeking suitable suppliers, signing contracts and supervising contract execution. If the manufacturer can produce some intermediate products within the enterprise itself, it can eliminate or reduce some transaction costs, and can better guarantee the quality of the products. Second, if the manufacturers need is a special type of specialized equipment, the supplier does not generally willing to specialize in only a buyer of the product of the investment and production, because this kind of proprietary investment risk is bigger. Therefore, vendors that need this specialized device need to solve the problem of specialized devices within the enterprise. In the end, the manufacturers hire employees with specialized skills, such as specialized product design, cost management, and quality control, and establish long-term contractual relationships with them. This can be more beneficial than buying the corresponding services from other vendors, thereby eliminating or reducing the corresponding transaction costs. So now that it is the end of the year, it is a good time to reflect on what we have done to achieve these goals. Block chain can create a world in which all requirements were met, everyone can express their own points of view, we can take meaningful global cooperation, can benefit through different experience. To exit a lost transaction, the most effective procedure is to issue a "stop loss order". Of course, the only way to do this is by the trader's idea of how much he's willing to lose. If he has set an acceptable level of loss before entering the trade, the only thing he can do is to issue a "stop loss order" once the market has reached that point. The independent of interest is of positive significance to show the active role of the fund users in the reproduction process.