A、To smoke in a public place. B、To make a fool of oneself. C、To smoke when a girl is in the room. D、To spit in the street. A

Social customs and ways of behaving change. Things that were considered impolite many years ago are now acceptable. Just a few years ago, it was considered impolite for a man to smoke on the street. No man who thought of himself as a gentleman would make a fool of himself by smoking when a lady was in the room.
    Customs also differ from country to country. Does a man walk on the left or the right of a woman in your country? Or doesn’t it matter? What about table manners? Should you use both hands when you are eating? Should you leave one hand on your lap, or on the table?
    The Americans and the British not only speak the same language but also share a large number of social customs. For example, in both America and England people shake hands when they meet each other for the first time. Also, most Englishmen will open a door for a woman or offer their seats to a woman, and so will most Americans.
    The important thing to remember about social customs is not to do anything that might make other people feel uncomfortable--especially if they are your guests. There is an old story about a man who gave a formal dinner party. When the food was served, one of the guests started to eat his peas with a knife. The other guests were shocked, but the host calmly picked up his knife and began eating in the same way. It would have been bad manners to make his guest feel foolish or uncomfortable.