Answer: Even though you have not provided the complete question, I have been able to locate it and to help with the answer. They ask you to complete the sentences with the appropriate article, provided that they need one. These are the sentences and the answers:
ORIGINAL TEXT: Tengo 23 años y soy estudiante. Soy (1) chico tranquilo y trabajador. Me gusta (2) naturaleza y no tengo (3) problemas con mis vecinos. Me gusta ir al cine y no me gusta (4) fútbol. Tengo buen humor por (5) mañanas y mejor humor por (6) tardes. Vivo en (7) apartamento en (8) quinto piso de (9) edificio muy moderno en Miami. Sólo tengo (10) pequeño problema: mi perro. Algunos dicen que tiene mal (11) carácter. Yo creo que es (12) buen animal, pero se siente solo, como su dueño.
ANSWERS:
1. un
2. la
3. no article needed
4. el
5. las
6. las
7. un
8. el
9. un
10. un
11. no article needed
12. un
Explanation: Just to elaborate a little on the answer, it can be added that in this exercise they ask you to complete the sentence with the appropriate article. Articles in Spanish, like in English, can be definite (the) or undefinite (a, an). And, in Spanish, articles have genre. So, for instance, in sentence 2, since the word nature is a singular feminine noun, you need to use the definite article "la." In sentence 7, since the speaker does not say in which specific apartment he lives—he just says that his apartment is located on a fifth floor— we use the indefinite article "un."
