Rewrite the sentences, changing the underlined direct object nouns to direct object pronouns. modelo tienes los documentos. los tienes. changed no tengo la llave de la habitación. you answered (blank) changed el botones pone el equipaje en el taxi. you answered (blank) changed juanita toma fotos en la playa. you answered (blank) changed mi tío compra un boleto para el partido de fútbol. you answered (blank) changed mis hermanas y yo buscamos a nuestros padres. you answered (blank) changed inés y luisa quieren ver los monumentos. you answered (blank) changed estamos explorando el centro de la ciudad. you answered (blank) changed laura está escribiendo unas postales. you answered (blank)

The Direct Object, is the part of the sentence that directly receives the action of the verb. It is used to replace a person, animal or thing in the conversation or in the writing in order to avoid repetition; when they have already been seen in a sentence or external context where the statement occurs.

In this context the Direct Object pronouns are:

1st person singular: Yo me

2nd person singular (informal): Tú te  

2nd person singular (formal): Usted lo/la

3rd person singular: El/eso lo, Ella/esa la

1st person plural: Nosotros nos  

2nd person plural: Ustedes(In latinAmerica) los/las/Vosotros(In Spain) os    

3rd person plural: Ellos/Ellas los/las

According to the explanation above and the list, we have to identify who directly receives the action of the verb and then replace it for its corresponding direct object pronoun:

1) No tengo la llave de la habitación (I do not have the key to the room)

In this sentence the element that receives the action of the verb tengo (I have) is la llave (the key), which is the 3rd person in singular feminine esa (it). Therefore the corresponding direct object pronoun is la:

(I do not have them)

2) El botones pone el equipaje en el taxi (The bellboy puts the luggage in the taxi)

In this sentence the element that receives the action of the verb pone (he puts) is equipaje (luggage), which is the 3rd person in singular masculine eso (it). Therefore the corresponding direct object pronoun is lo:

(The bellboy puts it)

3) Juanita toma fotos en la playa (Juanita takes pictures on the beach)

In this sentence the element that receives the action of the verb toma (she takes) is fotos (pictures), which is the 3rd person in plural feminine ellas (they). Therefore the corresponding direct object pronoun is las:

(Juanita takes them)

4) Mi tío compra un boleto para el partido de fútbol (My uncle buys a ticket for the football game)

In this sentence the element that receives the action of the verb compra (he buys) is boleto (ticket), which is the 3rd person in singular masculine eso (it). Therefore the corresponding direct object pronoun is lo:

(My uncle buys it)

5) Mis hermanas y yo buscamos a nuestros padres (My sisters and I are looking for our parents)

In this sentence the element that receives the action of the verb buscamos (we are looking for) is padres (parents), which is the 3rd person in plural masculine ellos (they). Therefore the corresponding direct object pronoun is los:

(My sisters and I are looking for them)

6) Inés y Luisa quieren ver los monumentos (Inés and Luisa want to see the monuments)

In this sentence the element that receives the action of the verbs quieren ver (they want to see) is mounmentos (monuments), which is the 3rd person in plural masculine ellos (they). Therefore the corresponding direct object pronoun is los:

(Inés and Luisa want to see them)

7) Estamos explorando el centro de la ciudad (We are exploring the city center)

In this sentence the element that receives the action of the verb explorando (exploring) is centro de la ciudad (city center), which is the 3rd person in singular masculine eso (it). Therefore the corresponding direct object pronoun is lo:

(We are exploring it)

8) Laura está escribiendo unas postales (Laura is writing some postcards)

In this sentence the element that receives the action of the verb escribiendo (writing) is postales (postcards), which is the 3rd person in plural feminine ellas (they). Therefore the corresponding direct object pronoun is las:

(Laura is writting them)