The third full day of competition at the London Olympics launched Monday, featuring 12 medal finals.

Four of the medals are in swimming. Swimmers will compete later Monday in the finals for the men's 200-meter freestyle and 100-meter backstroke and the women's 100-meter backstroke and 100-meter breaststroke.

Earlier, China won its second straight gold medal in men's synchronized 10-meter diving, while U.S. swimming star Michael Phelps began the defense of his 200-meter butterfly title — an event he has won at the last two Olympic Games.

At Wimbledon, Switzerland's Roger Federer and America's Serena Williams beat their respective opponents, extending their medal races to the next round.

Monday also features the finals in men's gymnastics. The women's basketball qualifying games include the United States against Angola.

A big question still hanging over the Olympics is – will fans be seen in the various venues to watch the athletes compete, as rows and rows of seats have so far been empty?

Olympic organizers blame sponsors for not using their seats. Organizers have promised to release tickets to local children and military personnel, and to sell more tickets.

The ticket situation has athletes and fans furious. Television shots at various events have revealed blocks of unused seats.

British newspaper “The Telegraph” said Monday it discovered at least 12,000 seats were empty Sunday.