Two men were walking in the African bush when they met a very hungry cheetah who eyed them ferociously. One of the men fished out some running shoes from his knapsack and bent down to put them on.
“Why are you doing that？” cried his companion in despair. “Don't you know that cheetahs can run over sixty miles per hour？”
“Yes， yes，” he replied as he finished trying the laces. “But I only have to outrun you.”