Which of the following was a cause of the ecological disaster known as the dust bowl?

a. excessive rainfall that year
b. a flood in california
c. a massive earthquake that loosened the topsoil
d. the plowing under of native grasses that kept topsoil in place

Identify the type of source based on the information provided. a historian found a journal belonging to an ancient indian princess. the princess liked to keep a record of all the royal women of her dynasty who lived before her time. she tried to collect as much accurate information about their history as possible. her journal is a great source of historical information. based on the passage, the princess’s diary is source.

Four score and seven years ago our fathers brought forth on this continent a new nation, conceived in liberty, and dedicated to the proposition that all men are created equal. —"the gettysburg address," abraham lincoln which quotation correctly uses an ellipsis to shorten lincoln’s words?

How did isolationism affect foreign policy?