GREY'S ANATOMY - "Don't Stand So Close to Me" - Recent events strain Burke and Cristina's relationship, Meredith's half-sister, Molly, is admitted to the hospital, and Mark and Derek must work together when two close-knit brothers seek medical help, on "Grey's Anatomy," THURSDAY, NOVEMBER 30 (9:00-10:01 p.m., ET) on the ABC Television Network. (ABC/KAREN NEAL) MARE WINNINGHAM, MANDY SIEGFRIED