—He was nearly killed by a car once. —Oh, when was ______ exactly? —It was in 2009 ______ he was riding a bike on the drive-way.
—What's the boys' favorite sport? —__________ of boys like playing football.
Every possible means __________ to prevent air pollution, but the sky is still not clear.
We must __________ to the public the simple fact thatdrugs are dangerous.
That was the first time __________ I __________ face to face with the president.
I walked up to the top of the hill with my friend, __________ we enjoyed a splendid view of the lake.