What was mexico's traditional economy based on until the 1940s

When air at the surface diverges, airflow above must diverge, regardless of hemisphere converge in the northern hemisphere but diverge in the southern diverge in the southern hemisphere but converge in the northern converge, regardless of hemisphere?

Why is terracing used in southeast asian agriculture?

Which of the following best describes the purpose of a nation’s boundaries? a. to limit the movement of goods and people b. to make it easier for cartographers to create maps c. to make the movement of goods and people easier d. to prevent other countries from invading territory