Only when class began ______that he had left his book at home.
The flu is believed by viruses that like to reproduce in the cells inside the human nose and throat.
His mother suggested he ______ to see the doctor, because his pale face suggested he ____ ill.
What I need is _____ book that contains ______ ABC of oil painting.
What a pity! I missed meeting my boss at the airport because my car was ______ in the traffic jam.
His physical disability makes _____ rather difficult for him to find a good job.