These problems are likely caused by urbanization.

air pollution
declining birth rate
forest overgrowth
housing shortages
overcrowding
volcanic eruptions
water pollution
water shortages

Pollution from one country can affect another. for example, south korea is especially affected by pollution and dust storms that come from

Most people can afford to spend approximately 2 ½ times their gross annual income for the purchase price of a home

Which of these scenarios is most similar to the aztec empire's system of agriculture? a. a farmer plants the same crops b. a farmer observes the behavior c. a farmer watches the sun’s patterns d. a farmer plants many different crops