For this, you'll always be giving two responses.... You'll answer the previous person's question, then pose a question of your own. Obviously they should be appropriate questions...
For instance, if the person before me posted:
Q. What's your favorite food.
I could then reply with:
A. Pizza
Q. What is your favorite Star Trek movie?
Got it? Okay, I'll start off...
Q. What is your favorite species from Star Trek?