【课文】 
MR.HALL：I left a suitcase on the train to London the other day.
ATTENDANT：Can you describe it,sir?
MR.HALL：It's a small blue case and it's got a zip.There's a label on the handle with my name and address on it.
ATTENDANT：Is this case yours?
MR.HALL：No,that's not mine.
ATTENDANT：What about this one?This one's got a label.
MR.HALL：Let me see it.
ATTENDANE：What's your name and address?
MR.HALL：David Hall, 83, Bridge Street.
ATTENDANT：That's right.D. N. Hall, 83, Bridge Street.
ATTENDANT：Three pounds fifty pence,please 
MR.HALL：Here you are.
ATTENDANT：Thank you.
MR.HALL：Hey!
ATTENDANT：What's the matter?
MR.HALL：This case doesn't belong to me!You've given me the wrong case!

David Hall 与 D. N. Hall 之间差别这么大，为什么 attendant 都能认错？

David Hall 与 D.N.Hall 意思是一样的吗？D 是 David 的缩写，那么N, 代表什么意思？