a profit maximizing firm in a competitive market is currently Glasses, also known as eyeglasses or spectacles, are devices consisting of glass or hard plastic lenses mounted in a frame that holds them in front of a person's eyes, typically using a bridge over the nose and arms which rest over the ears. Glasses are typically used for vision correction, such as with reading glasses and glasses used for nearsightedness. Safety glasses provide eye protection against flying debris for construction workers or lab technicians; these glasses may have protection for the sides of the eyes as well as in the lenses. Some types of safety glasses are used to protect against visible and near-visible light or radiation. Glasses are worn for eye protection in some sports, such as squash. Glasses wearers may use a strap to prevent the glasses from falling off during movement or sports. Wearers of glasses that are used only part of the time may have the glasses attached to a cord that goes around their neck, to prevent the loss of the glasses. Camping and hiking often represent very, very hard work, especially if you ought to bring many the different parts of an idea together so that you can make venture a hit. While the effort may be difficult, it can be a lot of fun once the plan all comes together as intended. Just make sure that you will get all of the right advice and knowledge available ensuring that you have a successful adventure. The market is the economic contact method which is the basic content of Commodity Exchange. Under the condition of commodity economy, the premise of exchange generation and existence is social division of labor and commodity production. Because of the social division of labor, the different producers, respectively, engaged in the production of different products, did not meet the needs of themselves and others and exchange their respective product, so that the general labor products into commodities, make the product production is transformed into commodity production. It is under this condition that the market for goods to be exchanged to meet the needs of different producers is born. Therefore, the market is the product of the division of labor and the exchange of goods under the conditions of commodity economy. The market and commodity economy have inalienable internal relation. At present, there are 89, 92, 95 and other labels on the market, which represent the octane value of gasoline, which means the anti-detonation of gasoline, which has nothing to do with the cleaning of gasoline. The so-called "high label gasoline is cleaner" is misleading. It is more scientific, more economical, and can give full play to the engine's efficiency according to the engine compression ratio or the requirement of the automobile instruction manual. Historical costs differ from current values All things in the world are constantly moving. In all attributes of matter, motion is the most basic attribute, and other attributes are specific manifestations of motion attributes. For example, spatial attribute is the broad embodiment of physical activity. Time attribute is the persistence of material movement. Material movement form is varied, for each specific material movement form the corresponding form of energy, such as: and macro mechanical movement of the object corresponding to the form of energy is kinetic energy; The energy form corresponding to the molecular motion is heat energy; The energy form corresponding to the atomic motion is chemical energy; The energy form corresponding to the directional motion of charged particles is electric energy; The energy form corresponding to the photon motion is light energy; And so on. The motion characteristics of two objects can be described and compared by some physical quantity or chemical quantity. For example, two objects that make mechanical motions can be described and compared by physical quantities such as speed, acceleration and momentum. The current can be described and compared with current strength, voltage, power and so on. , but when the movement form phase at the same time, not two material movement characteristics only can describe and compare each other quantities is energy, the energy feature is moving all the common characteristics of material, energy scale is measure all movement in the form of a general. Thus, a new philosophical definition of energy can be made. In 2010, China overtakes Japan being the other world's economy. According to economists, China remains to be a developing country with fast pace of growth. Data released that Japan\'s gross domestic product is $1.286 trillion while it is worth $1.335 trillion for China. Another source demonstrates Japan keeps growing at 2-3 percent in compared with 10 % a year of China.