---Someone’s been here. Who ___ it be? It looks like Helen.---It ___ be Helen.She is ill in hospital.
________ you understand the rule, you’ll find English easy to learn.
—Why, this is Henry speaking. —Oh, I’m sorry. I didn’t ________ your voice on the phone.
He spoke about the country as if he had been there, but ________ he had never.
Her friend did everything in his ________ to help with her business.
________ large number of people think ________ truth has been hidden on purpose.