CUBA: Residents are celebrating the release of the 3 political prisoners who had been unjustly held in the United States. ARGENTINA: Heads of state of the MERCOSUR trade bloc are meeting to discuss the free movement of people across borders. CUBA: Victims of Colombia's armed conflict are submitting their final testimony before an end-of-year pause. MEXICO: The federal government has denied being involved in the abduction of 43 students from the state of Guerrero.