An American woman visiting England was repeatedly offended -- even, on bad days, enraged -- when the British ignored her in settings in which she thought they should pay attention, for example, she was sitting at a booth in a railroad station cafeteria. A couple began to settle into the opposite seat in the same booth. They unloaded their luggage; they laid their coats on the seat; he asked what she would like to eat and went off to get it; she slid into the booth facing the American. And throughout all this, they showed no sign of having noticed that someone was already sitting in the booth. When the British woman lit up a cigarette, the American had a concrete object for her anger. She began ostentatiously(明显地,显眼地) looking around for another table to move to, of course there was none; that’s why the British couple had sat in her booth in the first place. The smoker immediately crushed out her cigarette and apologized. This showed that she had noticed that someone else was sitting in the booth, and that she was not inclined to disturb her. But then she went back, pretending the American wasn’t there, and her husband behaved similarly when he returned with their food and they ate it. Question: Why do you think the British couple pretended that the American wasn’t there?