听力原文：Americans eat breakfast and lunch quickly unless it is a social business or family occasion. The evening meal is usually longer and a time for families to gather together. Rushing through daytime meals is part of the fast pace in America. Another reason for rushing through daytime meals is that many people eat in restaurants that are usually crowded with people waiting for a place so that they too can be served and returned to work at the proper time. So each hurries to make room for the next person. As with busy people everywhere there is a real difference with meals that are eaten in a hurry and those that can be enjoyed slowly with friends. What is not mentioned in the passage?