Tom with his friends ______ volleyball since three o’clock

Would you have told him the answer had it been possible? .— I would have, but I _____ so busy then.

Professor Wu is a teacher respected by all of us, who always ________ new teaching methods to improve our English.[ ]

I didn’t hear you because I the news on the radio.

No one knows for certain how the first Americans arrived in _____ is now the United States.