—Who's the man talking to our teacher?—A professor __________ a visit to our school.
_____ how to express the idea in English, he turned to the dictionary.
He hasn’t slept at all for three days. _____ he is worn out.
There was such a long queue for coffee at the interval that we ____ gave up.
—How did your father deal with you? —We were lucky to _____ being punished.
The professor explained this theory so clearly that this phenomenon was easy enough ________.