business profit definition Sunglasses allow better vision in bright daylight, and may protect one's eyes against damage from high levels of ultraviolet light. Typical sunglasses are darkened for protection against bright light or glare; some specialized glasses are clear in dark or indoor conditions, but turn into sunglasses when in bright light. Most sunglasses do not have corrective power in the lenses; however, special prescription sunglasses can be ordered. Specialized glasses may be used for viewing specific visual information (such as stereoscopy) or 3D glasses for viewing three-dimensional movies. Sometimes glasses with no corrective power in the lenses are worn simply for aesthetic or fashion purposes. Even with glasses used for vision correction, a wide range of designs are available for fashion purposes, using plastic, wire, and other materials. Along with the social network virtualization, the market is not necessarily true place and place, many of today's business is achieved through the computer network, China's largest e-commerce site, taobao is to provide the exchange of virtual market. Taobao, Asia's largest online retail business circle, is committed to creating the world's preferred online retail business, founded by alibaba group on May 10, 2003. Taobao now spans two large parts of C2C (consumer) and B2C (merchant to individual). As of 2008, there were more than 98 million registered users, with the majority of online shoppers in China, covering the vast majority of online shoppers in China. In 2008, the transaction volume was 999.6 billion yuan, accounting for 80% of the online shopping market. 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. Meet with difficulties, clothing retailers in October and November for coat and knitwear sales was blocked by the untimely warm weather, while the housing market slowdown means DIY furniture chain and tough times. There are 3, 4, 5, 6, 8, 10 and 12 cylinders of the engine. The arrangement of cylinder mainly includes direct column, V shape, W shape, etc.