单项选择题

Passage 1

A great difference between American social customs and those of other countries is the way in which names are used. Americans have little concern for "rank", especially socially. (76) Most Americans do not want to be treated in any especially respectful way because of their age or social rank; it makes them feel uncomfortable. Many Americans even find the terms "Mr. ", "Mrs." or "Miss." too formal. People of all ages may prefer to be called by their first names. "Don’t call me Mrs. Smith, just call me Sally." Using only first names usually indicates friendliness and acceptance. However, if you do not feel comfortable using only first names, it is quite acceptable to be more formal. Just smile and say that after a while you will use first names but you are accustomed to being more formal when you first meet someone. Very often, introductions are made using both first and last names: "Mary Smith, this is John Jones." In this situation you are free to decide whether to call the lady "Mary" or "Miss Smith". Sometimes both of you will begin a conversation using last names, and after a while one or both of you may begin using first names instead. You have a choice: if you don’t want to use first names so quickly, no one will think it impolite if you continue according to your own custom.

In the first paragraph the author tells us that ______.