Escoge la oración en la que se usa el presente perfecto. a. la tribu murunahua navega el río tambopata desde hace muchos años. b carlos está navegando por el río tambopata en este momento. ccarlos ha navegado por el río tambopata esta mañana.

In Spanish grammar the Present Perfect tense is similar to the English grammar, and the rule is as follows:

Subject + verb Haber (to have) in present tense + verb in past participle + complement

It is used to express that an action took place in the past but continues in the present.

If we want to write a sentence in in Present Perfect tense, we have to follow the rule above, taking into account that the verb Haber in present also must be correctly written according to the subject pronoun.  

As follows:

1st person singular: Yo he  

2nd person singular: Tú has  

3rd person singular: Él/Ella/eso/esa ha  

1st person plural: Nosotros hemos

2nd person plural: Ustedes(In LatinAmerica)/Vosotros(In Spain) han   

3rd person plural: Ellos/Ellas han

Therefore, according to the former explanation and the rule described, the right answer is C:

Carlos ha navegado por el río Tambopata esta mañana. Carlos is the Subjectha is the conjugated form of the verb Haber in present with the 3rd person singularnavegado (sailed) is the main verb of the sentence in past participlepor el río Tambopata esta mañana is the complement of the sentence

In english is:

Carlos has sailed on the Tambopata River this morning.

1-b si, conocemos a tu amiga maria2-d saben

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