GREY'S ANATOMY - "Invest in Love" - A generous donation is offered to Seattle Grace by the parents of Arizona's 10-year-old patient. however, when his condition worsens, she finds herself in a conflict of interests. Meanwhile, Cristina tests her boundaries with Owen at the hospital, and adding insult to injury, Alex is left with all of Izzie's hospital bills to contend with, on "Grey's Anatomy," THURSDAY, NOVEMBER 5 (9:00-10:01 p.m., ET) on the ABC Television Network. (ABC/RANDY HOLMES) SANDRA OH