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.
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Question: Fact: a valley is formed by a river flowing

Answer: In what way are valleys formed?


Question: Fact: heat and pressure change the remains of prehistoric living things into natural gas

Answer: Over many, many years, the buildup of warmth and pressure can take a dinosaur's remains and change them into something that can?


Question: Fact: An example of a reproductive behavior is salmon returning to their birthplace to lay their eggs

Answer:
When fish travel in the opposite direction of flow they are going to?