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: white blood cell destroys pathogens in the body
How can you get your hands on white blood cells?

Fact: organisms can be preserved in sedimentary rock
What is the use of organisms preserved in sedimentary rock?

Fact: condensing causes a liquid to form

Which is the best example of condensation?