In the city of Chicago I met a man I will never forget. He drove a bus that ran from downtown to the edge of the city. Each night I watched him. As the passengers got on the bus, he smiled at each one. It was fun to see how many passengers forgot their troubles and smiled back. There was one passenger, I noticed, that had never smiled back. He usually coughed roughly through his mustache   as he got on the bus. And he never covered his mouth. But that wasn't enough to stop the bus driver's smile. He gave the man with the mustache and the rough cough his biggest smile. The man with the mustache never seemed to see that smile. He would sit on the edge of his seat and complained about the way that the bus driver was driving. He only complained for a short time, but he spoke loudly enough so everybody could hear. It was enough to make me sick. But the driver never said a word. He just went on smiling at passengers as they got on the bus. I wanted to get to know this bus driver better. One night I stayed on the bus to the end of the line. I asked the driver, "Why don't you throw that man with the mustache out of the bus?" The bus driver looked at me and gave me one of his famous smiles. "I don't care about that," he said. "Let me tell you about my friend's dog. The man next door to me has a dog. Every time the moon shines, the dog barks   and barks all night." "Well, what about the dog and the moon?" I asked. "Oh, the moon keeps on shining," he said. The writer stayed on the bus to the end of the line because he wanted  _  .
to listen to an interesting story to know more about the driver to ask about the dog and the moon to ask the driver to throw the man out