Councilman Bernard Parks and State Sen. Mark Ridley-Thomas, the candidates for county Supervisor in the June primary, are scheduled for their only televised debate on Thursday at 6:30 at the Westside Jewish Community Center on Olympic. Channel 7 anchor Marc Brown will moderate, but the debate won't air until an unspecified later date. Sponsors are the Los Angeles League of Conservation Voters and the League of Women Voters. Info.