Check-in desks are empty in Terminal 4 in the afternoon, in London Dec 19, 2010.Europe saw little respite on Sunday from the Arctic conditions that closed airports and disrupted travel over the weekend before Christmas, traditionally one of the busiest times of the year. London's Heathrow, the world's busiest international airport, which was forced to close both its runways for much of Saturday because of heavy snow, was not accepting inbound flights on Sunday and said only a few planes would be leaving. [China Daily/Agencies]