【题目】Only then _______________ that I had made a terrible mistake.

【题目】Huge amounts of paper ______ each day in China.

【题目】Volunteering gives you a chance _______ lives，including your own．

【题目】When he was young, he used to __________ hard at his lessons.

【题目】What will the man buy?

【题目】New York is ____ to the headquarters of the United Nations and many famous international companies.

【题目】The minute he heard someone shouting for help, out_______ to see what was happening.

【题目】______ we have planned ahead might change when we put it into practice．

【题目】When Kerry and Sam met again two years later，each was pleased to see ____．

【题目】There will still be lots of challenges if we are to _____ garbage in a short time.