Answer:
We must complete the blanks with pronouns:
1) Me gusta esta computadora.
Me gusta ______
In this sentence the pronoun is easy, you can see that the subject is "esta computadora"
So we have:
Me gusta esta.
2) Ese cantante es muy popular.
_____ es muy popular.
Now we are talking about "Ese cantante", so the pronoun here can be "el"
El es muy popular.
3)Aquellos senores son bolivianos.
____ son bolivianos
We are talking about "aquellos señores" that is in plural, so the correct pronoun can be "ellos"
Ellos son bolivianos.
4) Aquel gato es bonito.
_____ es bonito.
Here we are talking about "aquel gato", so a pronoun that completes the blank can be "ese" (means something like "that one")
Ese es bonito.