——Why didn’t you call me this morning?——I ______ call you. I called you all the morning, but I couldn’t ______.
----Hello, may I have an appointment with the headmaster? ---_____.
He is ready to help others, seldom, ______ refusing them when they turn to him.
Robert is said ______ abroad, but I don’t know which country he studied in.
I can remember very few ______ when he had to cancel his plans because of poor health.
He hurried to the booking office only ______ that all the tickets had been sold out.