I think we should get up early ______ we can catch the early bus.

The hotel ____ me ＄50 for a single room during one night.

I don’t think _____ possible to travel around the world without any modern equipment. [ ]

I can ______ some noise while I’m studying, but I can’t stand very loud noise.

___________ seems hard to believe is that the bird the officer uses is the same bird often seen in public parks—-the pigeons.