What should you do at the end of your speech to give the audience a sense of having come full circle?

By linking back to the introduction

Explanation:

In a book by James S. O'Rourke, IV named The Truth about Confident Presenting: All You Need to Know to Make Winning Presentations, Fearlessly and Painlessly.

He talks about how distinguished speakers realize that the secret to achievement is driven by only a few universal values.

You should think carefully about having a memorable conclusion. You may be questioning those interested, or you may be able to link back to the introduction and give the audience a sense of a full circle coming in.