Detailed Instructions: You need to read the given passage and construct a question about the information present in the passage. The question should be answerable from the passage. Most importantly, only those questions are allowed whose answers cannot be determined from a single sentence. Do not generate questions that require only a single sentence to answer. Instead, try to combine two sentences and create a question from that combination. Do not create open-ended questions, i.e., the answers to them cannot be found precisely from the information provided in the passage.
Q: Paragraph- Sent 1: Take a look at this train in Figure 1.11.
Sent 2: It looks very futuristic.
Sent 3: What do you notice about it?
Sent 4: Did you notice that the train has no wheels?
Sent 5: How can a train have no wheels?
Sent 6: It doesn't need wheels.
Sent 7: It actually floats, or levitates, just above the track.
Sent 8: Magnets enable the train to do this.
Sent 9: This is not a normal train.
Sent 10: This is a maglev train.
Sent 11: The word maglev stands for magnetic levitation.
Sent 12: Because it has no wheels, there is no friction.
Sent 13: Some magnets hold the train up.
Sent 14: Other magnets are used to move the train forward.
Sent 15: This train can go very fast.
Sent 16: It can reach speeds up to 480 kilometers (300 miles) per hour!
Sent 17: Magnets are pretty cool.
Sent 18: What exactly is a magnet?
Sent 19: How is it able to exert such force?.
A:
What is the role of magnets in maglev trains?