Q: 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.
Paragraph- Sent 1: You know that friction also causes heat.
Sent 2: Think about when you rub your hands together.
Sent 3: It is friction that makes them warm.
Sent 4: But why does this happen?
Sent 5: Friction causes the molecules on rubbing surfaces to move faster.
Sent 6: Faster moving particles have more heat energy.
Sent 7: Heat from friction can be useful.
Sent 8: Can you think of other places where you might find friction?
Sent 9: Friction also lets you light a match (see Figure 1.10).
Sent 10: Heat from friction can also cause problems.
Sent 11: It can cause a car to overheat.
Sent 12: To reduce friction, oil is added to the engine.
Sent 13: Oil coats the surfaces of moving parts.
Sent 14: This coating of oil makes them slippery.
Sent 15: When things are slippery there is less friction.
Sent 16: Have you ever seen a sign that says, slippery when wet?
Sent 17: This too has to do with friction.
Sent 18: Water, like oil, can reduce friction.
Sent 19: The wet surface may allow your shoes to slide more easily.
A:
Why do your hands become warmer when you rub them together?