Cows as they are today never existed in the wild and were domesticated from aurochs some 10,500 years ago.
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Blue whale arteries are large enough for humans to swim through and their hearts are the size of cars.
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Shark corneas are used in eye transplants and shark bone marrow can be used to graft human bones.
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It has been calculated that a single breath from a mature blue whale can inflate up to 2,000 balloons.
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Sergeant Stubby was the only war dog to be promoted to sergeant through combat in WWI. He saved his regiment from surprise mustard gas attacks, found and comforted the wounded, and even once caught a German spy by the seat of his pants, holding him there until American Soldiers found him.
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