Why does most of Mexico's population live in central Mexico? (NOTE: There's no option, this is the question itself on my Homework, and I am getting confused, any help in answers?)

Why are field trips an important part of education

Before tuberculosis was understood to be a communicable disease, and before the discovery of antibiotics to treat it, a major outbreak could kill or cripple a significant portion of a nation’s labor force. how would such an event affect the economy? illustrate the effect by dragging to shift either the aggregate demand curve or the long-run aggregate supply curve.

What is the role of institutions in society - do they perform positive functions, or simply work in the interests of the powerful and against the powerless? (a related question here is why do our life chances vary by class, gender and ethnicity)