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. 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. The response to multilayered values is rational. Rational (including abstract thinking with image thinking) is higher animals, are now known to have intelligent human only) on the basis of intellectual responses, to the further development of it by means of language, text or image will intellectual formed by various basic concept and basic image fixed in the form of the second signal system in the brain, and within the brain to be more complex, the deeper, longer series "sex", "rigid instinct", "elastic instinct" and "intellectual" and other forms of reaction. Among them, the cognition of the relation between the basic concepts forms the abstract thinking, and the person's understanding of the relation between the basic images forms the image thinking. Rationality is human to the second signal system of "reflection" type of reaction activity, it can find out the basic concept and basic image, more general internal relation and essence difference between to discover things between the movement of more general and more abstract and change rule. For example, people form "water" and "to..." through the practice of production and life. To ", "low" and "flow", the concept of nouns, prepositions, adjectives, verbs, between these concepts through a certain form of conditioned reflex established a mutual connection, thus obtained the "water flows downwards" such a logic rules.JuHua shares announcement to United Nations integrated circuit industry investment fund (hereinafter referred to as "funds"), and other joint venture set up in the giant core technology co., LTD. (hereinafter referred to as "the giant core technology"). The company has registered capital of 1 billion yuan, with a total of 390 million yuan invested by the company and the large fund, with a 39 percent stake in each other, and a 22 percent stake in other investors. Before that, what is the nature of the enterprise itself is an issue that has been ignored by traditional microeconomic theory. In the traditional microeconomic theory, is the manufacturer's production process as a "black box", namely enterprise is abstracted into a from input to output a "black box" of the pursuit of profit maximization.