The Thesis Oral
The thesis oral and defence is not your usual presentation. It is a formal setting. Your examiners will have read your work, and they expect certain things in your presentation. Handling questions is key.
The following resources may help you.
Nasty PhD Viva Questions by Andrew Board
Hints for PhD Defenses by Ed Coffman, Jonathan Rosenberg and Sal Stolfo, Columbia U.
Preparing for the Viva Voce (oral examination) of your thesis, produced by City University of London
How to survive a thesis defense by Joe Wolfe