Here are the correct forms of the words based on the prompts you provided:

1. The ao dai is the **traditional** dress of Vietnamese women. (TRADITION)
2. Tet holiday is the most important **celebration** for Vietnamese people. (CELEBRATE)
3. We have to be **careful** when riding our bikes on the streets. (CARE)
4. The old man walked **slowly** to the park. (SLOW)
5. The author's **happiness** is communicated through his song. (HAPPY)
6. We find Huong very **communicative**. (COMMUNICATE)
7. They went to see most of the **interesting** places. (INTEREST)
8. His sudden **death** must be a shock to her and her family. (DIE)
9. The other **competitors** admired him. (COMPLETE)
10. We can only get there by plane. There is no **choice**. (CHOOSE)

Feel free to ask if you need further assistance!