In which country is the city of Cancún?

In which country is the city of Winnipeg? In which country is the city of Halifax? In which country is the city of Guadalajara? In which country is the city of Monterrey? In which country is the city of Tijuana? In which country is the city of Acapulco? In which country is the city of Oaxaca? In which country is the city of Rio de Janeiro?