Eleven Washington, D.C.-area high school soccer players touched down in South Africa yesterday to teach the sport to (and bond with) young girls their age, many of whom are HIV positive or closely affected by the disease.  The D.C. Blast, an all-girls soccer team, raised $60,000 in the last year to fund their trip as part of Grassroots Soccer, a U.S.-based AIDS organization that uses soccer to teach African youth the skills they need to avoid contracting HIV.