query: How old is Mexico?
passage: History of Mexico
The history of Mexico, a country in the southern portion of North America, covers a period of more than three millennia. First populated more than 13,000 years ago,[1] the territory had complex indigenous civilizations before being conquered and colonized by the Spanish in the 16th century. One of the important aspects of Mesoamerican civilizations was their development of a form of writing, so that Mexico's written history stretches back hundreds of years before the arrival of the Spaniards in 1519. This era before the arrival of Europeans is called variously the prehispanic era or the precolumbian era.
passage: Twelfth grade
In Mexico, the twelfth grade is the last year of high school, where students are normally aged 17–18. As in Mexico the education is divided in "primaria" (6 years), "secundaria" (3 years) and "preparatoria" or "bachillerato" (3 years), the twelfth grade is usually called "tercero de preparatoria" (third grade of preparatory) or "Quinto y Sexto Semestre" (Fifth and Sixth Semester).