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.