Dude you need to figure out what you want to know about the program and ask that. Do you care how often call is? Do you care if residents miss their continuity clinics because they are post call? Do you care how many people leave the program each year?
Figure out what you want to know. I assume you are feeling sort of desperate or else you wouldn't have posted this. Even if this is the ONLY interview you get, you still need to know the things that are important to you.