A scientist name Charles had a strange idea. He wanted to invent a new kind of car which could go without a driver. It could also be used as a living room. That means you can go anywhere on your sofa in the car. You might say that it’s impossible. But Charles succeeded in making it in a factory and named it Tridika. Tridika has no wheels and it starts working when it reaches the magnetic levitation tracks（磁悬浮轨道）. It takes its energy from its tracks. And it works in the same ways as a magnetic train. It moves very fast. As everyone knows, cities are developing rapidly. There are more and more cars running on the road. So parking space is limited. Sometimes it’s hard to find a place to park（停车）. Tridika can solve this problem easily because it needn’t park on the ground. Actually, it can park on the outside wall of the building with the help of an elevator system（电梯系统）. In this way, much parking space can be saved. When Tridika parks itself in front of your apartment, you can get into your room directly. Of course, there must be a side door in the outside wall. Then Tridica becomes another living room. It’s really amazing, isn’t it? Tridika can hold six passengers. So you can go on vacation in it with your family in your free time. of course it can also be sued as an office while you are traveling on the road. That is to say, you can travel and work at the same time. 根据短文内容，选择最佳答案。（5分）
51. Who invented the new kind of car?
A. Charles B. A driver C. A factory worker D. A passenger
52. When does Tridika start working?
A. When it gets into your room. B. Before it parks on the outside wall. C. After it takes its energy from the wheels. D. When it reaches the magnetic levitation tracks.
53. What’s probably the meaning of the word “limited” in Para. 2?
A. 封闭的 B. 有限的 C. 开放的 D. 无限的
54. Why can Tridika save the parking space?
A. Because it can move very fast. B. Because it can hold six passengers. C. Because it needn’t park on the ground. D. Because it could be used as a living room.
55. Which is the best title（题目） for this passage?
A. Tridika: A free parking place B. Tridika: A fast magnetic train C. Tridika: A strange side door D. Tridika: A new driverless car