—Who______ it be that is knocking at the door? —It ______ be Father, but I’m not sure.
In fact, _______ one cause that leads to the problem.
The students _______ busily when Miss Brown went to get a book she _______ in the office.
Her father works as a ______ in a hotel and her mother a ______ in a private company.
. I think you must be mistaken about seeing him at the theatre; I’m sure he _____ abroad all week.
I found her sitting in the corner, reading _____ newspaper, with _____ in her eyes.