In which country is the city of Oaxaca?

In which country is the city of Monterrey? In which country is the city of Cancún? In which country is the city of Tijuana? In which country is the city of Acapulco? In which country is the city of Rio de Janeiro? In which country is the city of São Paulo? In which country is the city of Manaus? In which country is the city of Recife?