The answer is <u>sonó</u>
Yo me duchaba cuando <u>sonó</u> el teléfono.
The verb duchaba is in pretérito imperfecto and matches with simple past (in this case sonó). This pretérito imperfecto describes an action or state in the past, without indicating whether it was completed or not.
What does Gaston and Lucia decide to do? follow the recommendation of WHO? Why gastón and lucía want to get tickets for students? How and when can they get tickets for students? What happens when they arrive at the school office? What do they ask the secretary? Do you think they get the tickets?
