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

Input: Consider Input: A frog develops (a/an) lungs as it changes from a tadpole to an adult frog.

Output: Which of the following structures does a frog develop as it changes from a tadpole to an adult frog?

Input: Consider Input: Gravity makes soil and rock particles move gradually down the slope during each thaw.

Output: What makes soil and rock particles move gradually down the slope during each thaw?

Input: Consider Input: The strong affinity of concentrated sulfuric acid for water makes it a good agent for dehydrating.
Output: The strong affinity of concentrated sulfuric acid for water makes it a good agent of what?