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Lesson Plan
The Puzzle of Ice Age Americans
Students describe alternative theories for arrival of first humans to come to...
Tue, 12/01/2009 - 12:19
audio
Ediacaran Fossils: One Species at a Time
When the cod fishery collapsed in Newfoundland in the early 1990s, the hopes of the...
Thu, 10/27/2011 - 15:37