You will be given a definition of a task first, then some input of the task.
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: Heat supplies the energy that causes motion.
Sent 2: The deeper you go into toward the Earths core, the hotter it gets.
Sent 3: At the core it is really hot.
Sent 4: All that heat tries to rise toward the surface.
Sent 5: In the Mantle, the rock is partially melted and is able to move.
Sent 6: As it is heated, the material in the mantle moves toward the surface.
Sent 7: As the mantle material rises, it cools.
Sent 8: When it reaches the Earths crust, it is mostly stopped.
Sent 9: A little of the material can break through the surface, but not all.
Sent 10: Instead, it begins to move horizontally.
Sent 11: The mantle material moves horizontally away from a mid-ocean ridge crest.
Sent 12: Toward the surface, the mantle material starts to cool.
Sent 13: As it cools it sinks back down into the mantle.
Sent 14: These areas are where deep sea trench occur.
Sent 15: The material sinks back down to the core.
Sent 16: The system operates like a giant conveyor belt.
Sent 17: The motion due to heating and cooling is called convection.
Output:
Why does the material move horizontally?