perfectly competitive market profit maximization International online report (guo hao, China Radio International) : when it comes to South American wine, the first thing that comes to mind is the export of wine from Chile to Argentina. But in recent years, wine from the mountains of south Rio grande, southern Brazil, has been rising to prominence in the international wine market because of its crisp taste and high "cost performance". And China, a big consumer of wine, is a "key target" for Brazilian vintners. In the past year, Brazil has exported nearly 200,000 bottles of wine to China, and some Brazilian wineries have set up shop in China and even opened online stores. Brazilian red wine is quietly entering the Chinese people's table. Two extremes can be envisaged. In an extreme case, each production is done by a single individual, such as a person making a car. In this way, the person is going to trade with a lot of intermediate goods suppliers, and also to trade with the demanders of their products. In this case, all transactions are conducted through the market in many individuals. In another extreme cases, all the production in the economy in a large enterprise, such as the complete car was produced in the enterprise interior, don't need to make any intermediate products trading market. Therefore, the same transaction can be conducted either through the organizational form of the market or through the organizational form of the enterprise. Companies exist, or companies and markets coexist, because some transactions cost less in the enterprise, while others cost less in the market. 3. The role of securities investment The manufacturing capacity of the UK car is ranked by the top, which can be seen from the manufacturing scope of the product and the scale of the industry involved. The British automobile manufacturing scope covers include cars, commercial vehicles, buses, bus in various fields, such as mass production can be conducted at present, the UK has seven car manufacturers, eight commercial vehicle manufacturers, 11 bus passenger car manufacturers, more than 10 large premium cars and sports car manufacturers. According to the British association of automobile manufacturers and dealers, in 2013, Britain has 1.6 million cars, rolled off the production line is equivalent to have a new car every 20 seconds, 77% of products exported to all over the world. The level of car manufacturing in the UK is also attracting top manufacturers from around the world.