Answer: Anything really, but it depends on your likes and interests.
Explanation:
For example, if you like space, talk about the solar system, or talk about a specific planet, or how the universe was made, and you can come up with a 5 minute speech, if you really like the topic. so i would say find a topic you know a lot about and that you love. or maybe a topic that you love, but not know so much about, and this can give you the opportunity to learn more about it. hope this help.
