URL	Title	Id
http://digfir-published.macmillanusa.com/astro_interactive_exercise/ie_mechanism_of_plate_tectonics.html	Chapter 1. The Mechanism of Plate Tectonics	5139ebc9b11c0fc94e000000
http://digfir-published.macmillanusa.com/astro_interactive_exercise/ie_mechanism_of_plate_tectonics_dlap.xml	DLAP questions	5139ebc9b11c0fc94e000000