A Massachusetts man has been held on $12,500 bail after pleading not guilty to charges of drunken driving and leaving the scene of an accident on Interstate 290 in Worcester over the weekend that left a bread delivery truck driver dead. Prosecutors said at his arraignment on motor vehicle homicide charges Tuesday that 26-year-old Keith Leblanc of Auburn was drunk when he rear-ended the truck at about 4:30 a.m. Sunday. The driver, 45-year-old Duane Race of Putnam, Conn., was taken to a hospital and died Tuesday. Witnesses said the Jeep that rear-ended the truck never stopped. Police followed a trail of leaking automotive fluids to Leblanc’s home.