Please could someone help me? Select two issues.

The two issues that often contribute to the fall of civilizations are .
natural disasters
problems from within
lack of funds
outside invasions

the andes or andean mountains (spanish: cordillera de los andes) are the longest continental mountain range in the world, forming a continuous highland along the western edge of south america. this range is about 7,000 km (4,300 mi) long, about 200 to 700 km (120 to 430 mi) wide (widest between 18° south and 20° south latitude), and of an average height of about 4,000 m (13,000 ft). the andes extend from north to south through seven south american countries: venezuela, colombia, ecuador, peru, bolivia, chile and argentina.

from wikipedia

hope this !

the dust bowl, otherwise known as the dirty thirties, was a huge dust storm that killed multiple (and i mean  multiple) farmer's crops, leaving them homeless, and foodless, and jobless. in california, there were 5.7 million residents, and the population shrank as mexicans were repatriated. however, when the dustbowl happened, a lot of people began to move to california. by 1940, 250,000 people had arrived. therefore, your answer would be  the population increased, massively.  i hope this !

explanation: