1. mi tía es vive en guadalajara. 2. mi primo no es rubio, es 3. mi novio cree que la clase no es fácil; es 4. los libros son ; me gustan mucho. 5. mis hermanos son ; no tienen muchos amigos. 6. las gemelas tienen quince años. son

The words that could fill the blanks in each case are:

Mi tía es mexicana. Vive en Guadalajara. Mi primo no es rubio, es blanco. Mi novio cree que la clase no es fácil; es difícil. Los libros son interesantes; me gustan mucho. Mis hermanos son tímidos; no tienen muchos amigos. Las gemelas tienen quince años. Son quinceañeras.

Explanation:

The translation of the sentences is:

My aunt is Mexican. Lives in Guadalajara. My cousin is not blond, he is white. My boyfriend thinks class is not easy; it's hard. The books are interesting; I like them very much. My brothers are shy; they do not have many friends. The twins are fifteen years old. They are quinceañeras.

Since there are no options to choose the most appropriate word, I have selected for you those that I consider best apply to the context of the sentence, as I explain below:

"Mexicana" is chosen because it is mentioned that he lives in a state of that country. "Blanco" is chosen since it could be another option, in addition to brown or perhaps Caucasian. "Difícil" is the opposite of easy. Regularly when a book likes it very much, it is very "interesante." Shy people regularly have few friends. In many Latin American countries, girls who turn 15 are called "quinceañeras."