根据句意及所给汉语提示写出单词的正确形式。

1. We are all _____(自豪) of our motherland. It's great.

2. The boy shows great interest in _____(自然) science.

3. Welcome to our city _____(无论何时) you come!

4. No country can afford to neglect the _____ (教育) of its young people.

5. I think that _____ (二十一) century will bring us more hope.

6. He made a big d_____. He'll travel around the world all by himself.

7. Many people have known the i_____ of protecting the environment now.

8. My mother is very s_____  with me in my study. She never allows me to miss

lessons.

9. A_____ he had only entered the contest for fun, he won the first prize.

10. —What's the matter with you?

      —I have a toothache.

      —I think you should go to see the d_____ fight away.

甲数=2×2×2×3，乙数=2×2×3×5，甲数和乙数的最小公倍数是（    ）。