TASK DEFINITION: Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
PROBLEM: The combustion of propane gas produces carbon dioxide and water vapor.

SOLUTION: The combustion of propane gas produces carbon dioxide and what else?

PROBLEM: Herbivores is the term for animals that eat producers to get energy.

SOLUTION: What is the term for animals that eat producers to get energy?

PROBLEM: Mars planet is the easiest to observe.

SOLUTION:
What planet is the easiest to observe?