Even if the participants cannot ask questions, the press will be asking Kerry's questions for him, so Bush needs to be prepared for them as though Kerry himself is asking the questions...
"Bush needs to be prepared for them as though Kerry himself is asking the questions..."
Of course, but the thread is "What question (s) should George Bush pose to John Kerry during the debates?"
Bush can maybe put a question into a reply if it fits, but thats a big if. Otherwise, I see no way that he can throw out questions to Kerry.