The professor ________at 8 o’clock,but he has not shown up yet,which worries all of us.
Winter is the time of the yearthe days are short and nights are long.
--- What ______ when I phoned you? --- I ______ my work, and I was about to go out.
It was the first time ________ I ________ face to face with a thunder storm.
We were having a meeting _________ suddenly someone knocked at the door.
The old woman has _______________ too many hardships in the past 10 years.