Bicycle used to be the leading means of transportation in China's cities and villages, and China was once called "the Kingdom of Bicycles". Nowadays, with traffic congestion and air pollution becoming more and more serious in cities, riding a bicycle is becoming popular again. Recently, China's entrepreneurs have combined mobile Internet technologies with bicycles and invented the business model of bike-sharing. The appearance of shared bikes has made it more convenient for people to get around, and people can ride bikes at any time only with the help of a mobile phone. To encourage people to travel by bike, many cities have built bike lanes. Now, more and more Chinese people like exercising by riding bikes.