题目

Not so long ago, most people didn’t know who Shelly-Ann Fraser-Pryce was going to become. She was just an average high athlete. There was every indication that she was just another Jamaican teenager without much of a future. However, one person wanted to change this. Stephen Francis observed then eighteen-year-old Shelly-Ann at a track meet and was convinced that he had seen the beginnings of true greatness. Her times were not exactly impressive, but even so, he sensed there was something trying to get out, something the other coaches had overlooked when they had assessed her and found her l如图，在△ABC中， BD是∠ABC的平分线，过点C作CE⊥BD，交 BD的延长线于点E，∠ABC=60°，∠ECD=15°.(1)直接写出∠ADB的度数是_______；(2)求证：BD=AB；(3)若AB=2，求BC的长．