Final answer:
The Aztecs are considered civilized due to their complex civilization, including a well-planned city, advanced agricultural systems, and control of a large territory with a significant population.
Step-by-step explanation:
The Aztecs are considered civilized despite not being part of the Old World because they had a complex civilization with many accomplishments.
They built a well-planned and orderly city, Tenochtitlán, with specific neighborhoods for different occupations, a trash collection system, markets, and public buildings and temples.
They also had advanced agricultural systems, such as the construction of chinampas or 'floating gardens.' Additionally, their civilization had a caste system, developed robust trading routes, and controlled a large territory with a population of millions.