What are the two major problems facing historians who are investigating the fall of the Maya?

To scientists, it's something more: evidence of the drought that is suspected to have led to the demise of the Mayan civilization. They found that the ratio of titanium to aluminum changed in the ninth and 10th centuries, a period when the Mayan civilization in the Yucatan Peninsula went into decline.

Explanation:

july 1861 here you go hope it

answer; i believe the two groups were irish immigrants and chinese immigrants;