I have never imagined _______ such a good hotel in this town.
Don’t call me at 9:00 o’clock tomorrow morning ,when I_______a lecture at Harvard.
Simply ring me up, _______I’ll come to your help as soon as possible.
Environment-friendly Olympics requires Beijing to improve its environment, _______ turning it into an ecology-friendly city.
Over time,__________custom of kissing developed as_______way for adults to express their love for each other.
If we ___ the other road ,we might have arrived here in time for the meeting.