Yes / no, is the following a verifiable fact?
"Zucchini grow and are used as poison in some cultures of ancient times."
Your chain-of-thought:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Zucchini are not poisonous at all, and are actually very healthy. The answer is no.