根据句意及所给提示完成单词。

1. —_____ does your father go to work? 

    —By bus.

2. There're sixty _____ in an hour.

3. —How far is it from here?

    —About 3 k____.

4. The little girl always _____ (担心) about her studies.

5. The _____ (自行车) are very cheap.

6. What does she think of the _____ (运输)?

7. I don't think tigers d_____ on meat.

8. He has a _____  (快的) breakfast.

9. The two boys look  _____ (不同).

10. In China, bikes and buses are the most popular m_____  (方式) of transportation.

以On Aging of the Population为题，写一篇长为120～150词的小作文。