Candidates in the contested races for the Sudbury School Committee, Planning Board, and Park and Recreation Commission in this spring’s election will discuss the issues and answer questions from residents during the League of Women Voters of Sudbury’s 57th annual candidates’ night at 7:30 p.m. March 7. The free event will take place at the Goodnow Library, 21 Concord Road. Audience members will be able to submit questions that evening, as well as in advance via e-mail to sudburycandidatesnight@gmail.com  until 5 p.m. March 6. The election is March 25.