It never occurred to me you could succeed in persuading him to change his mind.
—Good morning. I've got an appointment with Miss Smith in the Personnel Department. —Ah, good morning. You ________ be Mrs. Peters.
It ________be the postman at the door.It's only six o'clock.
It ________ be the vocabulary that caused you the problem in the exercise because you know a lot of words.
—What are you doing this Saturday? —I'm not sure, but I ________ go to the Rolling Stones concert.
I'm going to Europe on vacation together with John if I ________ find the money.