sentences:  She has won over 50 singles matches, reached the semifinals of the US Open and the quarterfinals of the Australian Open and Roland Garros, in addition to winning over $1 million in prize money so far.Wimbledon champion Venus Williams was forced to withdraw on October 28 due to severe dizziness.In 2007, the American won three titles, winning Memphis, Seoul and her sixth Grand Slam title at the Wimbledon Championships.