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.