http://digfir-published.macmillanusa.com/gls_animated_graph/gls_5_1.html\tChapter 1. eFigure 5.1 \t5149faa3b11c0f380e000000 http://digfir-published.macmillanusa.com/gls_animated_graph/gls_5_1_dlap.xml\tDLAP questions\t5149faa3b11c0f380e000000