根据材料内容，选择最佳答案。

Mr. Green lives in a village (村庄), but he works in a big city. He goes to work by train every morning and comes back home in the same way.

    When he is reading a newspaper on the train this morning, a man behind（在……后面） him says "hello!" to him and begins to talk to him, "Your life is not interesting, is it ? You take the same train every morning, and you always sit in the same seat and read the same newspaper." "How do you know all that about me?" Mr. Green says angrily(生气的).

    "Because I always sit in the same seat behind you." The man answers.