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.

Fact: a complete electrical circuit is a source of electrical energy
Which is a complete circuit?

Fact: classifying means grouping materials by their properties
Which would be excluded from a list of objects with metallurgical properties?

Fact: the moon orbits the Earth

The moon orbits an object that orbits the?