Today is Primary Day, with polls open between 6 a.m and 9 p.m. There are (mostly Democratic) races all over the city, whether for City Council seats or borough-wide office like Manhattan DA, but the big ones are the Mayoral, Public Advocate and City Comptroller competitions. Comptroller Bill Thompson and City Councilman are facing off in the Democratic mayoral primary; Councilmen Bill De Blasio and Eric Gioia, former Public Advocate Mark Green and civil rights lawyer Norman Siegel are fighting for the PA spot; and Council members Melinda Katz, John Liu, David Weprin and David Yassky are vying to be Comptroller. The winner must get 40% of the vote, or there will be a run-off. Only registered voters can vote in the primary; for more information, the Board of Elections and check out Gotham Gazette's Guide for the Last Minute (Primary) Voter. And experts think turnout will be low—15-18%, 450,000-500,000 people (1.1 million voted when it was Koch vs. Dinkins in 1989)—since there's no big mayoral matchup. Photo: Ade in New York