The British are among the world’s greatest readers of newspapers. It’s been the custom ever since most people could read. But why do people want to do nothing but read while traveling to work in a train Perhaps they are tired, or else they sit behind a newspaper to shut themselves off from the world. All the same, most men would notice a woman struggling with a heavy case and jump up to help her and a pretty girl sitting opposite wouldn’t escape their attention, either. In this case a paper is useful because they can have a good look at her from behind it without her knowing. Perhaps they do not all do nothing but read. There are stories of girls and young men who met in the rush hour, got married, and went on traveling on the same train, hand in hand. The main idea of this passage is that______.
A．people do nothing but read in a train B．why people read newspapers when they travel by train C．when people go to work in a train, they do different things D．people in Britain are great newspaper readers