For this case we have the following sentence:
El ascensor no funciona (fuctioning, working). Yo uso la ________
What we must do is complete the sentence with the use of an alternative other than the elevator.
In a building or mall, when the elevator does not work, we use the stairs.
Therefore, the complete sentence is:
El ascensor no funciona (fuctioning, working). Yo uso la escalera.
The translation of the sentence in English is:
The elevator does not work. I use the stairs.
Answer:
"la escalera"
El ascensor no funciona (fuctioning, working). Yo uso la escalera.