What is the conjugation of these IR Sentences?

Does anyone know what my spanish teacher means by this? i need to use plural forms of the verb ser. and she asked me to use a couple of adjectives to describe the boys collectively and then the girls collectively?

Fill the blank with a la, a las, a los, or al. carlos no en el parque.

Nosotros no (asistir) a la clase ayer. asistirimos asistimos asistemos asistamos