根据句意用括号内所给汉语提示完成句子。
1. Little Tom always has _______ (奇怪的) ideas in his mind.
2. LiLei is a _______ (勤勉的) student, all the teachers like him very much.
3. Never be _______ (粗鲁的)to the elderly, it's impolite.
4. I'm sorry I _______ (忘记)to post the letter for you yesterday.
5.YueFei is a great person in Chinese _______ (历史).