Mr. Green lived in a small town, but he worked in an office in a big city. So five days a week he went to work by train every morning and came home the same way. One morning he took out his newspaper and began to read on the train. Behind him was sitting a man. The man wanted to talk with him. So he tapped (轻拍) Mr. Green on the shoulder and spoke to him, but Mr. Green did not know him. The man said, “You are not living a very interesting life, are you? You get on the same train at the same station at the same time every morning, and you always sit in the same seat and read the same newspaper.” Mr. Green put his paper down, turned around, and said to the man angrily, “How do you know all that about me?” “Because I’m always sitting in this seat behind you,” the man answered.