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. Solution: as long as the gasoline in the tank is exhausted, the extra gasoline vapor in the tank can be fired into the cylinder by the negative pressure of the engine, and no gasoline vapor will overflow. In 2017, the blockchain enters the public eye through bifurcation, CryptoKitties and ICO. Driven by investment opportunities and media attention, traditional businesses and consumers have begun to focus on the cryptocurrency and its underlying blockchain technology.