the choices is 13 , 21 , 23 , 25 ,

The following is a list of five of the world's busiest alrports by passenger traffic for 2015 Name Hartsfield-Jackson Capital International London Heathrow O'Hare Tokyo Location Atlanta, Georgia, United States Beijing, China London, United Kingdom Chicago, Illinois, United States Tokyo, Japan # of Passengers (in millions) 89 74 67 66 64 How many more millions of passengers few out of Atlanta than flew out of Chicago