It’s hard to believe____ the way out of the forest without the help of the local guide.
I tried to phone her, but even as I _____ she was leaving the building.
The students _______ busily when Miss Brown went to get a book she _______ in the office.
I think you must be mistaken about seeing him at the theatre; I’m sure he ____abroad all week.
They haven’t arrived yet but we _____ them at any moment.
I feel sure I _____ her before somewhere.