Why you should watch This Is Us, NCIS, and more
Frozen regions of the world, including the poles and the tops of mountain ranges, are explored. Featured: organisms that can survive in the coldest conditions on Earth. Narrated by Sigourney Weaver.
Grasslands, prairies, plains and savannas are examined, including areas of Mongolia, Africa and Papua New Guinea. Also: Arctic tundra.
Aquatic creatures are observed in their ocean habitats, including whale sharks, dolphins, crabs, eels and octopi.
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