Zhang Bo waves to family members and friends after landing at an airport in Chicago, the United States, on June 9, 2019. After flying 68 days and making 50 stops, 57-year-old Bo Zhang completed his second around-the-world flight and landed in Chicago on Sunday morning. On April 2, Zhang kicked off the flight in the same airport in Chicago. In 68 days, he flied through 21 countries in three continents and over three oceans, with total mileage reaching 41,000 kilometers. (Xinhua/Wang Ping)