GREY'S ANATOMY - "Let The Bad Times Roll" - The residents agonize over their oral boards, reliving every answer they gave during their exams; Arizona's close childhood friend comes to Seattle Grace for medical help; the doctors work on a patient who is missing one third of his skull; and Julia asks Mark to start a family with her. Meanwhile Catherine tells Richard that one of his residents has failed, on "Grey's Anatomy," THURSDAY, MAY 3 (9:00-10:01 p.m., ET) on the ABC Television Network. (ABC/ERIC MCCANDLESS) DEBBIE ALLEN, JESSE WILLIAMS