Víctor es amigo de Juan. Juan y Víctor son amigos. La película es para niños.
Explanation:
"Víctor es amigo de Juan". In English this means Victor is Juan's friend. Is the present tense of the third person singular of the verb "ser". "Juan y Víctor son amigos". It means Juan and Víctor are friends. In this case "son" is the present tense of the third person plural of the verb "ser". In the case of "La película es para niños", the verb ser is the third person singular of the verb "ser". In English it means that the movie is for kids.
I suppose that one of the major "firsts" that was achieved by Ellen and Jose was that they were able to explore a highly contested region without the aid of instruments.