Rex Grossman is back as starting quarterback of the Chicago Bears. And what a long road it has been. After countless hours of rehabilitation to overcome two major injuries, he was more appreciative than ever Monday of where he's been, and of where he wants to go. "It was tough to look through the window and see my teammates practicing when I'm in there doing something that is extremely boring," Grossman said shortly after Bears coach Lovie Smith announced he would start Sunday against Green Bay. "And now getting a chance to play, it's one of those things that is extremely gratifying. It's an opportunity I'm definitely going to take advantage of because of what I've been through. ... I've got a little bit more respect for the position I'm in." Grossman, who replaced struggling rookie Kyle Orton in the second half Sunday night and led the Bears to a 16-3 win over the Atlanta Falcons, gave the Bears' passing offense an instant charge and a spark it had been missing