It must be time for the bell to ring.
They must have this book in the library.
He must have recognized you by your photo in the papers.
He must be in at this time.
She must be trying to help you.
She must be waiting for you at home.
He must have already been ill.
The first experiment must have failed.
She must have known what she was going to do.
She must be fond of the child.
They must have taken the wrong turning.
He must have been taken there by car.