Choose the correct, most natural-sounding responses according to the context of the conversation:
OTHER TOURIST: Yes, I think so. We're just waiting for the tour guide to arrive.
OTHER TOURIST: Yes, it is. I guess the tour guide is running a little late... (5 MINUTES LATER)
TOUR GUIDE: I'm sorry everyone, the 4:30 PM tour has been cancelled. We're having some mechanical problems with our bus.
TOUR GUIDE: I'm not sure right now. We'll have to wait and see...
TOUR GUIDE: I'm not sure. They're fixing the bus right now. If they don't fix it in 30 minutes, I'll give all of you your money back.
TOUR GUIDE: About one hour.