question: What sentence would provide a factual answer to this question: "Sycamores have the worlds largest"

answer: a stem is a source of support for a plant

question: What sentence would provide a factual answer to this question: "Which of the following has a population of zero?"

answer: if a population decreases to zero then that organism is extinct

question: What sentence would provide a factual answer to this question: "An example of a learned behavior is"

answer:
if an animal is trained to do something then that something is a learned behavior