Answer:
1. Tratenla amablemente.
2. Tienen que pedírselo.
3. No pueden contratarlo sin permiso.
4. Tienen que ponerla muy baja.
5. No deben servirselas a los menores de edad.
6. No pueden organizarlas nunca más.
Explanation:
It is called a direct object (in traditional grammar, direct complement) to the function played by a syntactic constituent (phrase, pronoun or a substantive subordinate proposition), different from the grammatical subject, which is necessarily required by a transitive verb
it is the person or object on which the action expressed by the verb falls, it is a modifier of the predicate. The direct object can be expressed by pronouns: lo, la, los, las. Substituting the direct object of a sentence for one of these pronouns is a recommended way to verify that it is indeed the direct object.
The answer if the first one.
La maestra está enferma.
History
La guerra civil
el descubrimiento de América
La primera vuelta al mundo
Los reyes católicos