Twenty years ago, I drove a taxi for a living. Once at midnight, an old lady in her 80s took my taxi. She gave me an address, and then asked, "Could you drive through downtown?"

    "It's not the shortest way," I answered quickly.

    "Oh, I don't mind," she said. "I'm in no hurry. I'm on my way to a hospice (临终关怀医院）. I don't have any family left. The doctor says I don't have very long time."

    I quietly shut off the meter. "What route would you like me to take?" I asked.

    For the next two hours, we drove through the city. She showed me the building where she had once worked, the neighborhood where she and her husband had lived, the place where she danced as a girl. As the sun was rising, she asked me to go to the address she had given me.

    "How much do I owe you?" she asked, reaching into her purse.

    "Nothing," I said.

    "You have to make a living," she answered.

    "There are other passengers."

    "You gave an old woman a little moment of joy," she said. "Thank you."

    I drove into the fine morning light. Behind me, a door shut. It was the sound of the closing of a life. I drove aimlessly（漫无目的地），lost in thought. For the rest of that day, I could hardly talk. What if that woman had gotten an angry driver, or one who was impatient to end his shift? What if I had refused to take the run?

    Heroes come in all shapes and sizes. Many heroes are not even human, such as dogs, horses and cats. They are so brave and helpful that human beings are proud of them, too. Lucca, a 12-year-old dog, is a great animal hero. She is a retired US Marine Corps dog. On April 5, 2016 she received the Dickin Medal from PDSA in London, England. And PDSA will provide free medical care for the sick and wounded animals in need. The Dickin Medal was founded in 1943 by Maria Dickin.

    The Medal is the highest prize for animals working in wars in the world.

    Lucca is the first U.S. Marine Corps dog to receive the medal. As a search dog, Lucca's work was dangerous. She was trained to find hidden weapons and explosive devices. According to the US Marine Corps, Lucca protected the lives of thousands of soldiers, and no soldiers were killed while she was going around. She completed over 400 dangerous pieces of work during six years in Iraq and Afghanistan. In 2012, she lost her front left leg in an explosion while working in Afghanistan.

    Lucca is the 66th animal to receive the Dickin Medal. 30 dogs (including Lucca) have got the Medal as well as 32 World War II messenger pigeons, three horses and one cat.

    George Stephenson was born in 1781 in a poor family. He had to start work when he was only eight. When George was fourteen, he became his father's helper. He spent a lot of time learning about engines. On holidays, he often took one engine into pieces and studied each piece carefully. Soon he became a very good worker though he could not read or write.

    He began to learn the English letters when he was seventeen years old. Every day after he did twelve hours of hard work, he walked a long way to have lessons from a young teacher.

    On his eighteenth birthday, he wrote his own name for the first time in his life. George invented many things in his life. The train was the greatest one among them. Today when we watch or take trains from one place to another, we will think of this great man—George Stephenson.