伦敦为奥运做最后准备

London is welcoming around 10,000 athletes, hundreds of thousands of visitors and a worldwide television audience for the formal opening of the Olympic Games Friday.

Organizers have dealt with a series of last-minute problems, including scrambling to deploy enough security personnel, after a private contractor reported problems putting together a large enough force. 

Britain's Queen Elizabeth will officially open the games.  The competition in 26 sports runs until August 12.