Little Mary: I find in my history book there is always such number (1451-1560) after the name Christopher Columbus. Would you please explain why, sir?

Little Rose: I can tell her, sir. It was Columbus' telephone number!

小玛丽：我在历史书中发现，克里斯托弗·哥伦布这个名字后面老是有(1451-1560)这几个数字。老师，请您给解释一下好吗?

小罗斯：老师，我能告诉她。那是哥伦布的电话号码!