question: What sentence would provide a factual answer to this question: "A source of heat might be"

answer: a car engine is a source of heat

question: What sentence would provide a factual answer to this question: "Quartz may produce rainbows when light is shined"

answer: a quartz is made of six-sided transparent crystals

question: What sentence would provide a factual answer to this question: "Sedimentary rock may be a result of"

answer:
nearly all fossils are found in sedimentary rock