Given scientific fact as input, generate the question from this fact such that it can be answered from the input.

Input: Consider Input: The sun delivers power to the chemical factory chloroplasts.

Output: What delivers power to the chemical factory chloroplasts?


Input: Consider Input: A student should use a balance to compare the masses of two small rocks.

Output: Which tool should a student use to compare the masses of two small rocks?


Input: Consider Input: A negative enthalpy change is observed in an exothermic reaction.
Output: What enthalpy change is observed in an exothermic reaction?