She _____ me why she wanted to leave today.
_______ a chance, we are bound to visit the 2010 Shanghai EXPO.
The doctors did all they could _______ him _______.
-- You speak very good English! -- Thanks. I_______ English since I was a small boy.
_______ my teachers’ help, I wouldn’t have succeeded.
Not until _______ 18 years old _______ a right to vote.