完成句子。阅读下列各小题，根据括号内的汉语提示，用句末括号内的英语单词完成句子。

1. They worked day and night about three days _____ (一切才恢复) to normal. (return)

2. I can't imagine _____ (他们多么激动) when they received these Christmas presents. (how)

3. _____ (参加) eco-travel and you will find it will help you understand the importance of nature. (take)

4. Not _____ (知道如何解决) the problem, he turned to his teacher for help.( work)

5. The doctor insisted that the patient _____ (动手术) as soon as possible. (operate)

6. With _____ (一场致命的台风来袭), more than 600 people were listed as either dead or missing on

    August 21st, 2009 in Taiwan.( break)

7. To every one of us, _____ (被录取) Beijing University is a great honor. (admit)

8. The news spread quickly through the village _____ (战争已结束), making the villagers wild with joy. (end)

9. I'll pay you a visit tomorrow aftemoon if _____ (你方便). (convenient)

10. I would have come for the lecture given by Professor Lee the day before yesterday, but I _____ (没受到

      邀请). (invite)