A、A kind of alternative energy. B、A new chemical element. C、Ultrasonic waves. D、A new type of ultra-fast solitons. D由原文可知，伦茨教授通过

W: In science fiction movies, there are many examples of spaceships racing through space at the speed of light or faster. But is faster-than-light travel possible? In a new study, Erik Lcntz, an American physicist from the University of Goettingcn in Germany, has proposed a theory of how faster-than-light travel could be possible. Today, we are honored to have Prof. Lentz with us, talking about their discoveries.
M: Thank you. Now, after our research, we believe that travel to distant stars and planets could be possible in the future. But this can only be achieved if the spacecraft exceeds the speed of light.
W: We learned from our high school physics book that light can travel at about 300000 kilometers in one second.
M: Yes. Physicist Albert Einstein’s famous Theory of Relativity suggests that it is not possible to travel faster than light. So, our latest research on the subject has centered on theories beyond normal explanations of matter. We call for "hypothetical particles" and states of matter with unusual physical properties to permit faster-than-light travel.
W: So how did you carry out the research?
M: Well, we had a plan to permit superfast travel by creating a series of solitons (孤子) to provide the basis for a powerful propulsion (推动力) system. A soliton is a compact wave that keeps its speed and shape while moving with little loss of energy.
W: If this method works, could it permit travel at any speed?
M: Yes. The method uses the very structure of space and time arranged in a soliton to provide a solution to faster-than-light travel. Such a technology could be used to sharply reduce travel times.
W: If we can really reach a speed faster than light, space travel to other planets may become much easier.
M: The nearest star beyond our solar system is Proxima Centauri. Using the traditional rocket fuel, it would take about 50000 to 70000 years to reach Proxima Centauri. A trip using nuclear propulsion technology would take about 100 years. But a light-speed trip would take only four years and three months. Our plan promises the hope of faster-than-light-speed travel, which could lead to "distant interstellar travel within a human lifetime."
W: Is it promising to make your theory into reality?
M: Yes, but a lot of work will be needed to make the method become a reality. The research and development process is difficult, but certainly not impossible. Additional steps could happen over the next several years, with a fully operational version possible within the next 10 years.
W: That’s something we can look forward to.
M: I agree. I would like to see this technology in use in my lifetime.
1. Who is Eric Lentz?
2. What does Albert Einstein’s Theory of Relativity suggest?
3. What is the basis of Prof. Lentz’s propulsion system?
4. How can Prof. Lentz’ research help space travel?
5. What does Prof. Lentz say about his research?