根据句意及首字母或汉语提示，填写句中所缺的单词。
1. We must be p________ if we ask others questions.
2. Kate r________ a letter from her grandparents three days ago.
3. She is an e________ teacher, so we all like her class.
4. you must be careful to c________ the road. It's dangerous.
5. The teacher looks very angry. Do you know what h________?
6. She was very ________(紧张) while she was having a test.
7. It's not right for you ________(抄) others' homework.
8. She had a very unusual ________(经历) on last Sunday.
9. She wants to be a ________(科学家) when she grows up.
10. If you have a ________(机会) to go to America, take it.
