Ellie and Oscar were greeted by a strange looking creature named Zork. "Welcome to my spaceship, Ellie and Oscar," said Zork, giving them both a big hug customary of Plutonians.

Ellie, the more outspoken of the two, returned Zork's greeting and said, "Your skin is so cold. Is it always like that?"

"Yes," replied Zork, "my planet, Pluto, is the furthest planet from the sun. My species adapted to withstand the cold weather there. A process called natural selection favored my species to be cold-blooded. Therefore, I have adapted to fit my environment."

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