"Listen carefully to what I say,"  the time traveler said, "I shall tell you something that you will not agree."

    "Why will we not agree?" I asked.

    "Because the science and mathematics you know are not correct," he said. "You believe there are only three dimensions(三维空间)-length, breadth(宽) and thickness."

    "There is nothing to argue with that, "  the youngest member of our little group said.

    "Exactly!"  the time traveler answered, "But there is also a fourth dimension - time."

    "We all know about time, " another member of the group said. "Time passed."

    "I do not agree,"  the time traveler said, "Length, breadth and thickness do not pass. They stay in the same place in space.  We move about them. I can prove that time is the same. It does not pass. We move in time the same way that we move in breadth, length and thickness."

    None of us believed the time traveler, and we argued with him for many hours.

    "If we could travel back in time,"  the scientist said, "We could do things to change the future."

    "If we could travel forward in time," the doctor(博士) said, "we could do things that change our present."

    The time traveler smiled, "It is clear," he said, "that there is only one way I can show you that I am right. We must do an experiment. Please wait here."

    He left the room and soon returned, carrying what looked like a clock.

    "This is a model of a time machine. It took me two years to make it," the time traveler said. "I want all of you to understand that when I start the machine, it will immediately travel in time and disappear from the present."

    He turned to the youngest of all. "Give me your hand," he said.

    The young man put out his hand. The time traveler took it and placed it on the machine. Immediately, there was a sudden wind, and the little machine disappeared.

    I was certain this was not a trick, but the doctor was not so sure.

    "Are you asking us to believe," he said, "that the machine is now in a different time?"

    "Certainly! In my laboratory, a full-size machine is almost complete. As soon as it is complete, I shall send myself on a journey through time. Would you like to see my machine?"

    "Are you serious about this?" the doctor asked.

    "I have never been more serious about anything," the time traveler said, "Come."

    We followed him to his laboratory. There, we saw the actual machine, not quite complete, but large enough for a man to sit in.

    I am a fifteen-year-old girl in a junior high school. I have a problem now. I hope you can give me advice. Three months ago, I knew a boy on the Internet. I found that he had the same hobbies as me, so we got on well soon. Two weeks ago we began to talk on the phone. We both felt comfortable when talking to each other, as if（好像）we had been good friends for a long time. Last week we met because he doesn't live far from my home. We talked a lot and enjoyed ourselves together in the gym.

    However, some of my friends said that I shouldn't make friends on the Internet. They also said that the boy might be dangerous. I don't know what I should do. I don't want a close relationship with him, but I'm really happy with him. Should I talk about this problem with my parents or teachers? I'm afraid that they would be angry and think I'm a bad girl. So I am turning to you for advice. Please help me.

    Three travelers, Allan, Carl and Paul were sitting on the chairs in a train station. They were waiting for a train that was very late.

    To kill time, they began talking to each other.

    At first, they talked about the weather and their work. Then Paul said, "Tell me-what would you most like to do if your doctor tells you that you have only three months to live?"

    The other two men thought about this for a while, then Carl spoke.

    "Well," he said, "if I have only three months to live, I'll take all my money out of the bank and go to foreign countries for holidays with my best friend, Erik. I'd like to travel to the places in the world as many as possible. And I'll stay at the best hotels and then eat the best food. I think I'll have a wonderful time. "

    "That's very interesting." Paul said.

    With these words, he turned to the other man, saying, "And what about you?"

    "I'll tell you a secret," Allan said. "I always want to be a racing driver. So if I have only three months to live, the first thing I'd like to do is to sell my house. With the money I'll buy the fastest car in the world. Perhaps I can enter all the big motor races."

    Then he laughed, "I might even end up world champion (冠军). "

    "Now it's your turn," Allan went on, "If your doctor tell you the bad news, what would you most like to do?"

    "Oh," said Paul with a smile. "__________________________"

    "Haha! Why didn't we think of that?" The three of them laughed together.