Annotation 1: a contanental puzzle https://classroom.google.com/c/Nzk1NTE3OTg3OTM4/a/ODA4MzUyMDgyNDA1/details
Annotation 4: atomic zoom in
CER:plate mation
CER: Plate motion https://docs.google.com/document/d/1GGRZmvxkaJBBDl1LyBA2VBTO1YLvWLERERbY-t2iIC8/edit?usp=sharing
CER chemical plate motion