Positive economic profit is sometimes described as excess profit. “We are a trade specialist so all retail enquiries and enquiries from smaller independent installers are handled by our customers, which means they are sharing directly in the success of our campaign.” A historical experiment. In 1934, the Chrysler corporation of the United States first adopted a streamlined body design. In 1937, German design genius fernand porsche began designing cars resembling the beetle. Not only did the beetle crawl on the ground, but it also flew in the air, and its physical resistance was small. Dr Porsche maximized the merits of the beetle's appearance, making "vw" cars the representative work of streamlined cars at the time. The "golden age" of the beatles was the "golden age" of the car from the 1930s to the late 1940s. Frances O 'grady, chief secretary of the UK federation of industry and industry, said: "this suggests that brexit uncertainty has damaged the household budget. Work and living standards must be a priority in determining the best choice for brexit. The government should maintain a single market membership at the negotiating table. " Lay the foundation In fact, value has its objective existence form and its subjective reflection form. Subjective value can be divided into two specific forms: values and emotions. Among them, values are people's understanding of absolute value, or people's understanding of value absoluteness. Emotion is the perception of relative value, or the relative understanding of value. Values (or emotional) and the value of relationship in essence is the relationship of subjective and objective: on the one hand, the objective value decision and restricts the subjective value, subjective value is to reflect the objective value, based on the objective value, and around the objective value fluctuates up and down; On the other hand, subjective value has certain relative independence, and has a certain reaction to objective value, which can induce, strengthen or restrict the objective value.