Voir means "to see", not "to watch." "We are watching the bear" would be best translated as Nous regardons l'ours.
My answer was identical to the given answer but was adjuged wrong. Only difference was the first word was not capitalised
Although "we are seeing the bear" is correct, usually the form "be + ing" expresses an action that is still ocurring and translates to "être en train de" in French. In that case, "we are seeing the bear" becomes "nous sommes en train de voir l'ours"
Hope this clears it up