---How about your travel ? ----You can hardly imagine what difficulty we had ___the vast desert .
Johnson knows much about the movie, I think that he must have seen it,________?
It was dark. We decided to___________for the night at a farm house.
. I have taught hundreds of students,___________ having been working in their fields for years.
______, he still cannot make himself understood.
_________ is unknown to us all.