Yes! there isn’t anything wrong with the sentence.
The answer is escucha.
The subject here is Marta, and we have to conjugate the verb to match the subject, which is a 'she' and you just add 'a' to the stem.
comllo=ate (make sure you add ~ on top of the ll in comllo)
The friends ate in the school cafiteria.
Answer:
2. Estoy en la sala leyendo un periodico
3. Estoy en el jardin, bebiendo una limonada
4. Estoy en el cafe hablando con unos amigos
