question: What sentence would provide a factual answer to this question: "Which is likely to be seen at the zoo?"

answer: some animals live in zoo exhibits

question: What sentence would provide a factual answer to this question: "Which of the following would be excluded from a list of ecosystems?"

answer: the Earth contains many ecosystems

question: What sentence would provide a factual answer to this question: "If a lizard is unable to obtain sufficient nutrients in a period of time, the resulting effect may be"

answer:
an animal needs to eat food for nutrients