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: matter vibrating can cause sound
Steve's ears alerted him to something. It was?

Fact: when a river floods , that river deposits sediment in flood plains
More dirt and sand gets deposited in a flat area near a river whenever?

Fact: an incandescent light bulb converts electricity into heat by sending electricity through a filament

Which is a byproduct of a lightbulb?