In this exercise, we need to choose the correct subject pronoun when addressing to someone and when talking about someone. So this is the explanation:
El Señor Díaz
Señor means Mr. so we address him in a formal way using the formal you, which is usted.
To talk about a man we use the third person singular in masculine form, which is él.
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Jimena y Marissa
It matches vosotras (informal) or ustedes (formal). This is so in Spanish, but in Latin America is more often the use of ustedes both in formal and informal way.
It matches the third person plural in feminine form.
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Maru y Miguel
Just as explained in Q3 but in masculine form.
Just as explained in Q3 but in masculine form.
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La profesora
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Un estudiante
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El director de una escuela
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Tres chicas
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Un pasajero de autobús
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Juan Carlos y Felipe
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Una turista
