party etiquette question

[Guest guest]

I'm going to a firm party this Sat night, cocktails and hors'doeuvres at

a fancy hotel downtown. I don't go to many events like this! When a

waiter approaches you with a tray of hors'doeuvres, how much do they tell

you about what it is, and how can you politely figure out if it's something

that is acceptable to you as a vegetarian? I want to make a good

impression, don't want to draw attention to myself and refuse all food (but

I will eat before I come), and I definitely don't want a mouthful of

chicken!

 

Thanks!

Audrey S.