Question

Why are air pollution levels higher in Mexico City than in other similarly densely populated cities?A.because Mexico City is surrounded by mountains that trap polluted air B. because Mexico City receives a large amount of precipitation each year C.because Mexico City contains more cars and buses than other large cities D.because Mexico City engages in more industrial activity than other large cities

Answer 1

A. because Mexico City is surrounded by mountains that trap polluted air.

The city sits in a high-altitude basin surrounded by mountains, which promotes temperature inversions and prevents dispersal of vehicle and industrial emissions, leading to higher pollution and photochemical smog. (B is wrong—more precipitation would wash out pollutants; C and D may contribute but do not explain why pollution stays high compared with similarly dense cities.)