Here are the completed sentences using the correct forms of the words in brackets:

1. He is a famous **actor**.
2. He **apologized** for his wrongdoings.
3. He plays soccer **beautifully**.
4. This is the biggest **building** in the city.
5. Bill Gates is a famous **businessman**.
6. Hoa has a fine **collection** of stamps.
7. You must **decide** the answer you choose.
8. She welcomes us **deeply**.
9. There is no **difference** between my answer and his.
10. We have a lot of **difficulties** in learning English.
11. Nam is very **economical** and heavy.
12. I felt very **excited** when I was a member of our school.