The student did what they ___ the old man.
Our eating habits have changed, ______ has our way of life.
We mustn’t waste anything; ______, we mustn’t waste our time.
A lesson from the terrible drought(干旱) that hit some parts of southwestern China this year is that more anti-drought projects ______ built in the past years.
—Where did you get this book? —Oh, I ______ it in the bookshop when I was looking for another one.
The plane of the Polish president was about to land ______ it snagged(挂) treetops and crashed, ______ the president and 96 others on board.