It depends on the subject, and what pronouns it passively carries.
Answer:
1. sabes
2. sé
3. conocen
4. sabemos
5. sabe
Explanation:
The exercise aims for you ro practice the usage and conjugation of the verb saber and conocer (to know).
Basically in Spanish there is a main difference between these verbs:
Saber: This is related to the knowledge of a fact or certain information.
Conocer: This is related to be familiarized to a person or place.
Here is the conjugation of both verbs in the indicative form of present:
SABER
PRESENTE
Yo sé
Tú sabes
Él/Ella/Ud. sabe
Nosotros sabemos
Vosotros sabéis
Ellos/Ellas/Uds. saben
CONOCER
PRESENTE
Yo conozco
Tú conoces
Él/Ella/Ud. conoce
Nosotros conocemos
Vosotros conocéis
Ellos/Ellas/Uds. conocen
