Answer and explanation:
In this exercise, we need to replace the direct objects with direct object pronouns. Recall that a Direct Object is a noun that receives, in an direct way, the action of a verb and the Direct Object Pronoun replaces the direct object. So let's solve this problem as follows:
Modelo:
El padre le compró un carro a Juan para su cumpleaños.
El padre se lo compró para su cumpleaños.
1. La camarera te sirvió el plato de pasta con mariscos.
Here el plato de pasta con mariscos, that matches the third person singular in masculine form, receives directly the action of the verb servir, so we replace this noun by the direct object pronoun that also matches this person, which is lo. So:
La camarera te lo sirvió
2. Isabel nos trajo la sal y la pimienta a la mesa.
Here la sal y la pimienta, that matches the third person plural in feminine form, receives directly the action of the verb traer, so we replace this noun by the direct object pronoun that also matches this person, which is las. So:
Isanbel nos las trajo a la mesa
3. Javier me pidió el aceite y el vinagre anoche.
Here el aceite y el vinagre, that matches the third person plural in masculine form, receives directly the action of the verb pedir, so we replace this noun by the direct object pronoun that also matches this person, which is los. So:
Javier me los pidió anoche
4. El dueño nos busca una mesa para seis personas.
Here una mesa, that matches the third person singular in feminine form, receives directly the action of the verb buscar, so we replace this noun by the direct object pronoun that also matches this person, which is la. So:
El dueño nos la busca para seis personas
5. Tu madre me consigue unos melocotones deliciosos. ¿Te recomendaron este restaurante Lola y Paco?
Here unos melocotones deliciosos, that matches the third person plural, receives directly the action of the verb conseguir, so we replace this phrase by the direct object pronoun that also matches this person, which is los. On the other hand, este restaurant, that matches the third person singular, receives directly the action of the verb recomendar, so we replace this noun by the direct object pronoun that also matches this person, which is lo. So:
Tu madre me los consigue. ¿Te lo recomendaron Lola y Paco?