(Mister/Madam) chairman.
May I have a word?
If I may, I think...
Excuse me for interrupting.
May I come in here?

Giving Opinions

I'm positive that...
I (really) feel that...
In my opinion...
The way I see things...
If you ask me,... I tend to think that...

Asking for Opinions

Are you positive that...
Do you (really) think that...
(name of participant) can we get your input?
How do you feel about...?