Here are the correct forms of the words provided:

1. I think staying at home all day is **boring** because I don’t know what to do. (BORE)
2. It is **unhealthy** to eat a lot of sweetened food and drinks. (HEALTH)
3. I love **making** pottery because it is challenging. (MAKE)
4. Many people do volunteer work because it can make a **difference** in their community. (DIFFER)
5. Some students usually teach street **children** English in the summer. (CHILD)
6. Water **puppetry** began in the 11th century. (PUPPET)
7. My father’s friend is a great **painter**. (PAINT)
8. Who is your favourite **musician**? (MUSIC)
9. English is an **interesting** and important subject. (INTEREST)
10. Ba is a famous stamp **collector**. (COLLECT)
11. English is an **interesting** and important subject. (INTEREST)
12. He accepts her **invitation** right away. (INVITE)