Given the task definition and input, reply with output. 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: Rough surfaces create more friction than smooth surfaces.
Sent 2: Thats why cars have tires.
Sent 3: Its also why we use rubber mats in areas that might get wet.
Sent 4: In your bathtub, you may even use No-Slip tape.
Sent 5: No-slip is another way of saying the items has a lot of friction.
Sent 6: In Figure 1.9, the blades of the skates are very smooth.
Sent 7: Thats why you cant slide across ice with shoes.
Sent 8: The soles of your shoes are much rougher than skates.
Sent 9: The rougher surface of shoes causes more friction and slows you down.
Sent 10: Heavier objects also have more friction.
Sent 11: A heavy object presses down with more force.
Sent 12: The surfaces are held together more tightly.
Sent 13: This makes the surfaces harder to slide past each other.
Sent 14: Did you ever try to push something heavy across the floor?
Sent 15: Heavy objects are much harder to push than light objects.

In order to slide across ice more easily, would you want something on your feet that had a smooth surface or a rough surface?