Recently I found/read a very interesting article on TNW regarding things you should never say during presentations.
The complete article can be found here and the high level overview is mentioned below:

1: I’m very jet-lagged/tired/hungover
2: I’ll get back to that later
3: Can you hear me? Yes you can!
4: I can’t see you because the lights are too bright
5: Can you read this?
6: Let me read this out loud for you
7: Shut off your phone/laptop/tablet
8: No need to write anything down or take photos, the presentation will be online later
9: Let me answer that question right away
10: I’ll keep it short

Good luck with your next presentation!