question: What sentence would provide a factual answer to this question: "If pollution is caused by many things, it is least likely to be caused by"

answer: riding a bike does not cause pollution

question: What sentence would provide a factual answer to this question: "Which is true?"

answer: the composition of something can be used to identify that something

question: What sentence would provide a factual answer to this question: "If you eat food that lots of microorganisms have been on, you could get"

answer:
microorganisms cause food to spoil