Mr. Green worked in an office in London, but he lived in the country and came to work by train every day. The station was not very far from his office, and he always went on foot from the station to his office and back from his office to the station. Every evening he walked past a poor man near a bridge. The man sat at the road and sold matches, and there was a dog near him. There was a piece of wood round the dog's neck, and the words "I AM BLIND" were on the piece of wood. Mr.Green was a kind man. He always stopped and gave a penny to the man, but he did not take any of his matches. One day, Mr.Green had a lot of work in his office and left the office very late. He came to the man and his dog, but he did not stop. The poor man stood up quickly, ran after him and said, "You're always very kind to me. Give me a penny today. I'm a poor man." Mr.Green stopped and he was surprised. Then he said, "You're a blind man. How did you see me?" The poor man said, "No, I'm not blind. My dog is." Mr.Green went to his office   _  .
by train first by train and then on foot on foot first on foot and then by train