Hello, let me help you with this problem:
We use definite articles when thinking that the reader or listener knows which particular thing or person we are talking about. On the other hand, indefinite articles are used to refer to a particular person or thing when the reader or listener doesn't know which one is being described.
SPANISH DEFINITE ARTICLES:
el - masculine singular form
la - feminine singular form
los - masculine plural form
las - feminine plural form
SPANISH INDEFINITE ARTICLES:
un - masculine singular form
una - feminine singular form
unos - masculine plural form
unas - feminine plural form
Both definite and indefinite articles must match the noun they modify in both gender and number.
According to this, our answers are:
1. _____________ país (indefinite article)
Un país
2. _____________ nacionalidad (definite article)
La nacionalidad
3. _____________ computadoras (definite article)
Las computadora
4. _____________ programa (definite article)
El programa
5. _____________ cosa (indefinite article)
Una casa
6. _____________ videos (indefinite article)
Unos videos