Given a fact, create a question that can be answered using the fact. Construct the question such that it is unambiguous, has a unique answer and the answer can be given using the fact.

Example Input: Fact: processes sometimes produce waste products
Example Output: What product eventually will become human waste?

Example Input: Fact: if a liquid disappears then that liquid probably evaporated
Example Output: If a liquid disappears then what probably happened to it?

Example Input: Fact: if a population decreases to zero then that organism is extinct
Example Output:
How low must be a population of some species drop before it is extinct?