question: What sentence would provide a factual answer to this question: "The substance that the respiratory system takes in from the air is released by"

answer: the respiratory system takes in oxygen from the air

question: What sentence would provide a factual answer to this question: "What slows down the transfer of heat?"

answer: a thermal insulator slows the transfer of heat

question: What sentence would provide a factual answer to this question: "A brick wall stops"

answer:
no light shines through an opaque object