For this case we have the following dialogue:
Elena: ¿De dónde eres Carlos?
Carlos: Soy de Cuba y mis compañeros son de Estados Unidos. ____________________ son (They are) de Texas.
We note that we must translate the expression in parentheses to fill in the blank.
The expression in parentheses represents the third person of the plural.
For this case, the third person in the plural is male.
Therefore, the correct word is:
"Ellos"
The complete dialogue is:
Elena: ¿De dónde eres Carlos?
Carlos: Soy de Cuba y mis compañeros son de Estados Unidos. Ellos son (They are) de Texas.
Answer:
C. Ellos
Answer: Question 1 is A. C is wrong because without much notice would be informal. B is wrong because posting it on the newspaper it would be visible to everyone even people you don't know.
Question 2 The answer would be B because Madrid is the largest city in Spain. Answer A and C is wrong because both of them are true.
Question 3 the answer is B. Sorry I can't give an explanation I have to go. Let me know if these answers are correct.
Explanation:
Answer: Estoy, Estás, Está. Estamos.
Estoy I am
Estás you are (singular informal)
Está he is / she is / you are (singular formal)
Estamos we are
Estoy comiendo. I am eating.
¿Estás bien? Are you okay?
Está chica es pequeña. This girl is small
Estamos pasando muy bien. We are having a good time.
Hope this helps! :}