To keep safe _______ an earthquake, you should remain at a spot in your room where nothing may fall on you.
She reached the top of the hill and stopped ________ on a big rock by the side of the path.
In some parts of London, missing a bus means ________ for another hour.
—The light in the office is still on. —Oh,I forgot ________.
—You were brave enough to raise objection at the meeting. —Well, now I regret ________ that.
-----Has any of you reached the Great Wall ? -----__________.