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: melting is when solids are heated above their melting point
A plastic toy reduced to a puddle was left on a?

Fact: harming an animal species causes that animal 's population to decrease
Hunting any kind of animal will eventually cause that species population numbers to?

Fact: if two equal forces in opposite directions act on an object then that object will stay in the same place

if two students of equal strength pull a double sided cup in opposite directions, what will happen?