根据句意用所给词的适当形式填空.
1. I don't know what made him laugh so _____ (excite)?
2. Andy Law will give two _____ (perform) in Nanjing this year.
3. He made a _____ (decide) not to go there this week.
4. Most international _____ (busy) letters are written in English.
5. "We are proud of your _____ (successful), Daniel." said father.