In the face of market failure, coase has given the opposite answer: external-utility problems can be solved by explicitly using the market, without government intervention. And zhang wuchang is more absolute, he said that there is no so-called external utility, there is only unclear property rights. Anyway, coase brought revolutionary innovation to market concepts. He made it clear that the key to the market was not the "price mechanism" of impersonal machinery, but the power of participants in economic activity. Well, the most recent trend within the dental industry and practices is usually to select locum tenens dentist. They are temporary dentists that appeal to certain requirements of the particular clinic limited to a few days and soon move over to a new clinic. This trend continues to be accepted in the field of medicine since a long time, however the trend has currently influenced the dental practice. One of the major factors behind the rapid expansion of this trend is the demand for dentists has increase along with the numbers of professionals usually are not sufficient to enough to focus on the requirements. As a result, just one individual creates a short lived basis in numerous clinics and chambers. 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. In 2010, China overtakes Japan to become 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 signifies that Japan keeps growing at two or three percent in weighed against 10 % annually of China.