Why didn't Caroline recognize the customer straight away ?
A:I bought two expensive dictionaries here half an hour ago,
but I forgot to take them with me.
B:Who served you, sir?
A:The lady who is standing behind the counter.(柜台)
B:Which books did you buy？
A:The books whick are on the counter.
B:Did you serve this gentleman half an hour ago, Caroline?
He said he is the man who bought these books.
C:I can't remember.
The man who I served was wearing a hat.
B:Have you got a hat, sir?
A:Yes, I have.
B:Would you put it on, please?
A:All right.
B:Is this the man that you served, Caroline?
C:Yes.
I recognized him now.