When I get nervous i try to study as much as i can so i know that ill know what im going to be talking about. Or ill ask to go to the bathroom calm down and realize that i know what hes asking. The stage check instructor isnt out there to get you, hes just trying to see what you know. Also try not to start talking about things you dont know much about, hell start to dig deeper.

And if your unsure...look it up to be sure. Good Luck.