During Hoover's administration, the stock market collapsed. This was such a huge deal because people were borrowing money from the banks and putting in stock market. When the collapse occurred people were unable to repay the banks the money they took out, the banks failed.
Answer:
He built early textile mills and helped improve power looms.
Explanation:
FCL built the Lowell Mill - hence "mills".
The answer is C.
As a science website says, "Scientists think they know why the Ancestral Puebloans disappeared. The primary culprit, studies suggest, was a megadrought that would have made it impossible to grow enough food to feed the tens of thousands of people living in the region."
If you didn't know, drought represents the lack of rain.