Several years ago, an experiment on endurance was conducted at the University of California at Berkeley. The experiment involved placing Norwegian field rats in a tub of water, where they were forced to swim until they grew exhausted and finally drowned. During the first experiment, the researchers discovered that on the average, these rats were capable of swimming for over seven hours before drowning.
A second experiment was conducted, exactly like the first but with one exception.This time, when a rat was getting too exhausted to swim any longer, the researchers would remove the rat from the tub of water for a few seconds, then put the rat back into the water to continue swimming. These rats were able to swim for almost 20 hours before perishing.
The researchers concluded that the rats in the second group were able to swim so much
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