Here are the complete sentences using "will" or "won't":

1. Their team **will** be champion.
2. People **will use** less private vehicles in the future.
3. Who **will make** the last decision?
4. The countryside **will disappear** in the future because of urbanization.
5. What **will they do** to reduce traffic jams?
6. **Will** it **rain** tomorrow?
7. She **won't** want to see him.