21 Puzzle Earth: The Biography Worksheet Set with Keys. Includes crosswords, fill ins, mix and matches, and word searches for all five episodes of the National Geographic Channel series Earth: The Biography. Ice, Volcanoes, Atmosphere, Oceans and Rare Planet. Applicable to science, Earth science, geophysical science, geology, astronomy, meteorology, oceanography, life science, biology, ecology, and the environment. A great companion to the National Geographic Channel series Earth: The Biography. By Derrick Neill.