A few to keep in mind:
- "And then what?"
- "Where are you going to get the money?"
- "Specifically who is going to do exactly what by precisely when?"
- "If this somehow doesn't work out, what do you think would be the likely reason?"
- "Do they mean the same thing we mean when they use that term?"
- "What is it you don't want to see?"
- "How does this move us forward?"