URL	Title	Id
http://digfir-published.macmillanusa.com/astro_interactive_exercise/ie_black_hole_structure.html	Chapter 1. Black Hole Structure	51413862b11c0ff21a000002
http://digfir-published.macmillanusa.com/astro_interactive_exercise/ie_black_hole_structure_dlap.xml	DLAP questions	51413862b11c0ff21a000002