Education in Mexico in a country where English is one of the official languages, offers an English-medium curriculum other than the country’s national curriculum and is international in its orientation." This definition is used by publications including The Economist. In central Mexico, the history of education stretches back to the prehispanic era, with the education of Nahuas in schools for elites and commoners. A formal system of writing was created in various parts of central and southern Mexico, with trained experts in its practice. After the Spanish conquest of the Aztec Empire, friars embarked on a widespread program of evangelization of Christianity. In
What Is and What Should Never Be and What Should Never Be" was performed live at Led Zeppelin concerts between 1969 and 1973. A live version taken from a performance at the Royal Albert Hall in 1970 can be seen on the "Led Zeppelin DVD". Another was included on disc two of the live triple album "How The West Was Won". Two more versions were included in BBC Sessions. What Is and What Should Never Be "What Is and What Should Never Be" is a song by English rock band Led Zeppelin. It was written by Jimmy Page and Robert Plant and was included as the second