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1 Cold-blooded animals are those animals in which the temperature of the blood changes with the temperature of their surroundings. Warm-blooded animals, on the other hand, maintain under normal conditions an almost constant temperature. The temperature of the human body, for example, is 98.6° F., which is usually higher than the temperature of the earth, air, and water; consequently when we touch a fish or frog, the animal feels cold.

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LOUIS PASTEUR

CHEMIST AND BIOLOGIST

He saved more lives than Napoleon took in all his wars."

See pages 168-170

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