question: What sentence would provide a factual answer to this question: "One way we pollute could be"

answer: pollution is a source of pollutants

question: What sentence would provide a factual answer to this question: "Liquids"

answer: Matter in the liquid phase has variable shape

question: What sentence would provide a factual answer to this question: "sound can be heard when it reaches what?"

answer:
when sound reaches the ear , that sound can be heard