Here are suitable words to fill in the blanks:

1. **on**
2. **a star**
3. **figure**
4. **called**
5. **called**
6. **red**
7. **gifts**
8. **written**
9. **in**
10. **on**

So the completed text reads:

Christmas is always held **on** December twenty fifth every year. Every family in England decorates a Christmas tree and puts **a star** in the middle of the living room. And Santa Claus plays an important **figure** in this festival. There is a poem to relate him. In 1823, the patron saint of children, Saint Nicholas appeared in a poem **called** A Visit Saint Nicholas. The character in the poem **is called** a **red** suit and gave children **gifts** on Christmas Eve. The poem, which was **written** by Clement Clarke Moore, an American professor, became popular **in** the USA. Santa Claus is based **on** the description of Saint Nicholas in this poem.