Answer: Although you have completed some of the answers, these are all the correct answers:
1. pidieron
2. tinto
3. refrescos
4. leche
5. se los
6. hamburguesas
7. prefirió
8. más
9. Se las
Step-by-step explanation: Just to elaborate a little on the answer, it can be added that in this exercise, which describes a scene in a restaurant, they are asking you to complete the sentence with the missing word—a noun (hamburguesas, leche), a verb (prefirió), an adverb (más), or a pronoun (se las). It is important to stress that in sentences 5 and 9 you are using a personal pronoun ("se") accompanied by the pronouns "los" and "las," which refer, respectively, to the dishes ("los platos") and the drinks ("las bebidas").