According to _____ US First Lady Michelle Obama, China is _____ fifth most popular destination for Americans studying abroad.
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.