英语笑话:An Exact Number（准确数字）

A tourist was visiting New Mexico and was amazed at the dinosaur bones lying about."How old are these bones?" the tourist asked an elderly Native American, who served as a guide. "Exactly one hundred million and three years old. "How can you be so sure?" inquired the tourist. "Well," replied the guide, " a geologist came by here and told me these bones were one hundred million years old, and that was exactly three years ago.