Final answer:
The correct form of the verb ayudar in the sentence is ayudábamos.
Step-by-step explanation:
The correct form of the verb ayudar to complete the sentence is ayudábamos.
The imperfect tense is used to describe ongoing or repeated actions in the past, while the preterit tense is used to describe completed actions in the past. In this sentence, the action of helping the organization every summer was an ongoing or repeated action in the past, so the imperfect tense is the correct choice.
Example: Nosotros ayudábamos a la organización cada verano cuando asistíamos a la universidad.
Learn more about Spanish verbs