Answer:
We need to complete the sentences with the right option:
1) Yo ____ digo la verdad a vosotros.
There are two ways of complete this, the more "correct" one is "os"
Yo os digo la verdad a vosotros.
There is other more commonly used, is "le"
Yo le digo la verdad a vosotros.
2) Nosotros __ decimos la hora a ellos.
Here the subject is "ellos", so the righ answer is "les"
Nosotros les decimos la hora a ellos.
3) Teresa ___ de la cámera a mi.
i think there is a typo here, the sentence must be:
Teresa ___ dio la camara a mi.
Here the speecher is talking about how teresa gave the camera to him, so the right option is "me"
Teresa me dio la camara a mi.