根据下列句子所给汉语注释或上下文，写出空缺处各单词的正确形式。

1. They flew to Scotland in a balloon _______ (成功).

2. It's every _______ (市民) duty to keep our neighborhoods clean and tidy．

3. Do the clothes need _______(熨烫)?

4. We can see many dead fish in the _______ (污染)  river.

5. If the heavy rain _______( 继续) to fall, the small village will be in danger.

6. Would you like to see the maple (枫树) _______ (叶)  in Hongmei Park ?

7. All of the students were excited about Yao Ming's _______ (到达).

8. —Just now a car was out of  _______ and hit a tree by the road.

    — Bad luck!

9. Tim and I are good friends, and we keep our secrets to _______.

10. —Could you tell me the _______ of  the building?

      —It's  about 1000 metres tall. There are 30 floors in all.