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.

[EX Q]: Fact: the earth has more mass than the moon
[EX A]: Which is the least massive?

[EX Q]: Fact: an animal can survive in an environment with little food by storing fat
[EX A]: A bear in the arctic can go a long time without eating?

[EX Q]: Fact: a valley is formed by a river flowing
[EX A]:
In what way are valleys formed?